diff --git a/prompto-lab-app/pom.xml b/prompto-lab-app/pom.xml
index 43abca9..edb1d71 100644
--- a/prompto-lab-app/pom.xml
+++ b/prompto-lab-app/pom.xml
@@ -123,6 +123,12 @@
             <artifactId>fastjson</artifactId>
             <version>2.0.57</version>
         </dependency>
+        <dependency>
+            <groupId>org.projectlombok</groupId>
+            <artifactId>lombok</artifactId>
+            <version>1.18.30</version>
+            <scope>provided</scope>
+        </dependency>
 
     </dependencies>
     <build>
diff --git a/prompto-lab-app/src/main/java/io/github/timemachinelab/core/qatree/CommonQA.java b/prompto-lab-app/src/main/java/io/github/timemachinelab/core/qatree/CommonQA.java
new file mode 100644
index 0000000..19c4b45
--- /dev/null
+++ b/prompto-lab-app/src/main/java/io/github/timemachinelab/core/qatree/CommonQA.java
@@ -0,0 +1,17 @@
+package io.github.timemachinelab.core.qatree;
+
+import lombok.Data;
+
+@Data
+public class CommonQA extends QA {
+
+    public CommonQA() {
+        super(QAType.QA);
+    }
+
+    private String question;
+
+    private String answer;
+
+
+}
diff --git a/prompto-lab-app/src/main/java/io/github/timemachinelab/core/qatree/FormQA.java b/prompto-lab-app/src/main/java/io/github/timemachinelab/core/qatree/FormQA.java
new file mode 100644
index 0000000..ce4c968
--- /dev/null
+++ b/prompto-lab-app/src/main/java/io/github/timemachinelab/core/qatree/FormQA.java
@@ -0,0 +1,19 @@
+package io.github.timemachinelab.core.qatree;
+
+import lombok.Data;
+
+import java.util.HashMap;
+import java.util.Map;
+
+@Data
+public class FormQA extends QA {
+
+    private String question;
+
+    private Map<String, String> answerMap;
+
+    public FormQA() {
+        super(QAType.FORM);
+        answerMap = new HashMap<>();
+    }
+}
diff --git a/prompto-lab-app/src/main/java/io/github/timemachinelab/core/qatree/QA.java b/prompto-lab-app/src/main/java/io/github/timemachinelab/core/qatree/QA.java
new file mode 100644
index 0000000..e9b0566
--- /dev/null
+++ b/prompto-lab-app/src/main/java/io/github/timemachinelab/core/qatree/QA.java
@@ -0,0 +1,14 @@
+package io.github.timemachinelab.core.qatree;
+
+public abstract class QA {
+
+    protected final QAType type;
+
+    protected long createTime;
+
+    protected long updateTime;
+
+    public QA(QAType type) {
+        this.type = type;
+    }
+}
diff --git a/prompto-lab-app/src/main/java/io/github/timemachinelab/core/qatree/QAType.java b/prompto-lab-app/src/main/java/io/github/timemachinelab/core/qatree/QAType.java
new file mode 100644
index 0000000..3bc31e6
--- /dev/null
+++ b/prompto-lab-app/src/main/java/io/github/timemachinelab/core/qatree/QAType.java
@@ -0,0 +1,14 @@
+package io.github.timemachinelab.core.qatree;
+
+public enum QAType {
+
+    QA("QA"),
+    SELECTION("Selection"),
+    FORM("Form");
+
+    private String name;
+
+    QAType(String name) {
+        this.name = name;
+    }
+}
diff --git a/prompto-lab-app/src/main/java/io/github/timemachinelab/core/qatree/QaTree.java b/prompto-lab-app/src/main/java/io/github/timemachinelab/core/qatree/QaTree.java
new file mode 100644
index 0000000..906e84c
--- /dev/null
+++ b/prompto-lab-app/src/main/java/io/github/timemachinelab/core/qatree/QaTree.java
@@ -0,0 +1,34 @@
+package io.github.timemachinelab.core.qatree;
+
+import lombok.Data;
+import lombok.Getter;
+
+import java.util.HashMap;
+import java.util.Map;
+
+public class QaTree {
+
+    @Getter
+    private QaTreeNode root;
+
+    private Map<String, QaTreeNode> nodeMap = new HashMap<>();
+
+    public QaTree(QaTreeNode root) {
+        this.root = root;
+        nodeMap.put(root.getId(), root);
+    }
+
+    public void addNode(String parentId, QaTreeNode node) {
+        QaTreeNode parent = nodeMap.get(parentId);
+        if (parent == null) {
+            return;
+        }
+        parent.append(node);
+        nodeMap.put(node.getId(), node);
+    }
+
+    public QaTreeNode getNodeById(String id) {
+        return nodeMap.get(id);
+    }
+
+}
diff --git a/prompto-lab-app/src/main/java/io/github/timemachinelab/core/qatree/QaTreeDomain.java b/prompto-lab-app/src/main/java/io/github/timemachinelab/core/qatree/QaTreeDomain.java
new file mode 100644
index 0000000..6717c5c
--- /dev/null
+++ b/prompto-lab-app/src/main/java/io/github/timemachinelab/core/qatree/QaTreeDomain.java
@@ -0,0 +1,20 @@
+package io.github.timemachinelab.core.qatree;
+
+import org.springframework.stereotype.Component;
+
+@Component
+public class QaTreeDomain {
+
+    public QaTree createTree(String userStartQuestion) {
+        CommonQA startQA = new CommonQA();
+        startQA.setQuestion(userStartQuestion);
+        QaTreeNode startNode = new QaTreeNode(startQA);
+
+        return new QaTree(startNode);
+    }
+
+    public QaTree appendNode(QaTree tree, String parentId, QaTreeNode node) {
+        tree.addNode(parentId, node);
+        return tree;
+    }
+}
diff --git a/prompto-lab-app/src/main/java/io/github/timemachinelab/core/qatree/QaTreeNode.java b/prompto-lab-app/src/main/java/io/github/timemachinelab/core/qatree/QaTreeNode.java
new file mode 100644
index 0000000..b55f5fc
--- /dev/null
+++ b/prompto-lab-app/src/main/java/io/github/timemachinelab/core/qatree/QaTreeNode.java
@@ -0,0 +1,44 @@
+package io.github.timemachinelab.core.qatree;
+
+import lombok.Data;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.UUID;
+
+@Data
+public class QaTreeNode {
+
+    private final String id;
+
+    private Map<String, QaTreeNode> children;
+
+    private QA qa;
+
+    public QaTreeNode(QA qa) {
+        this.id = UUID.randomUUID().toString();
+        this.children = new HashMap<>();
+        this.qa = qa;
+    }
+
+    public void append(QA qa) {
+        QaTreeNode node = new QaTreeNode(qa);
+        this.append(node);
+    }
+
+    public void append(QaTreeNode node) {
+        children.put(node.getId(), node);
+    }
+
+    public QaTreeNode getChild(String id) {
+        return children.get(id);
+    }
+
+    public boolean hasChild(String id) {
+        return children.containsKey(id);
+    }
+
+    public void removeChild(String id) {
+        children.remove(id);
+    }
+
+}
diff --git a/prompto-lab-app/src/main/java/io/github/timemachinelab/core/qatree/SelectionQA.java b/prompto-lab-app/src/main/java/io/github/timemachinelab/core/qatree/SelectionQA.java
new file mode 100644
index 0000000..3c6b4b2
--- /dev/null
+++ b/prompto-lab-app/src/main/java/io/github/timemachinelab/core/qatree/SelectionQA.java
@@ -0,0 +1,14 @@
+package io.github.timemachinelab.core.qatree;
+
+public class SelectionQA extends QA {
+
+    public SelectionQA() {
+        super(QAType.SELECTION);
+    }
+
+    private String question;
+
+    private String[] options;
+
+    private Integer selectedOption;
+}
diff --git a/prompto-lab-app/src/main/java/io/github/timemachinelab/core/session/Session.java b/prompto-lab-app/src/main/java/io/github/timemachinelab/core/session/Session.java
new file mode 100644
index 0000000..e84b984
--- /dev/null
+++ b/prompto-lab-app/src/main/java/io/github/timemachinelab/core/session/Session.java
@@ -0,0 +1,4 @@
+package io.github.timemachinelab.core.session;
+
+public class Session {
+}