diff --git a/src/main/java/site/easystartup/easystartupcore/project/domain/model/Project.java b/src/main/java/site/easystartup/easystartupcore/project/domain/model/Project.java
index b922ff3..c8a6fa6 100644
--- a/src/main/java/site/easystartup/easystartupcore/project/domain/model/Project.java
+++ b/src/main/java/site/easystartup/easystartupcore/project/domain/model/Project.java
@@ -43,7 +43,7 @@ public class Project {
     @JoinColumn(name = "owner_id")
     private User owner;
 
-    @OneToMany(mappedBy = "project")
+    @OneToMany(mappedBy = "project", cascade = {CascadeType.ALL})
     private List<Participant> participants;
 
     @Column(name = "created_date")
diff --git a/src/main/java/site/easystartup/easystartupcore/project/service/ProjectService.java b/src/main/java/site/easystartup/easystartupcore/project/service/ProjectService.java
index c24551f..77ccff9 100644
--- a/src/main/java/site/easystartup/easystartupcore/project/service/ProjectService.java
+++ b/src/main/java/site/easystartup/easystartupcore/project/service/ProjectService.java
@@ -4,46 +4,62 @@ import lombok.RequiredArgsConstructor;
 import org.springframework.stereotype.Service;
 import site.easystartup.easystartupcore.project.domain.model.Project;
 import site.easystartup.easystartupcore.project.repo.ProjectRepo;
+import site.easystartup.easystartupcore.service.UserService;
 
 import java.security.Principal;
+import java.util.Arrays;
 import java.util.Set;
 
 @Service
 @RequiredArgsConstructor
 public class ProjectService {
     private final ProjectRepo projectRepo;
+    private final UserService userService;
 
 
     public Project createProject(Project project, Principal principal) {
-        return null;
-    }
 
-    public Project updateProject(Project map, Long projectId, Principal principal) {
-    }
+        project.setTechnology(technologyToString(project.getTechnology()));
+        project.setOwner(userService.getUserByPrincipal(principal));
 
-    public void deleteProject(Long projectId, Principal principal) {
+        return projectRepo.save(project);
     }
+//
+//    public Project updateProject(Project map, Long projectId, Principal principal) {
+//    }
+//
+//    public void deleteProject(Long projectId, Principal principal) {
+//    }
+//
+//    public Project getProjectById(Long projectId) {
+//    }
+//
+//    public Set<Project> getAllProjectsForUser(Long userId) {
+//
+//
+//    }
+//
+//    public Set<Project> getAllProjectsWithTechnology(String technology) {
+//    }
+//
+//    public Set<Project> getAllProjectsForCurrentUser(Principal principal) {
+//    }
+//
+//    public Set<Project> getAllProjectsWithPosition(String nameOfPosition) {
+//    }
+//
+//    public Object applayOnProject(Long projectId, Principal principal) {
+//    }
+//
+//    public Object confirmParticipant(Long projectId, Long participantId, Principal principal) {
+//    }
 
-    public Project getProjectById(Long projectId) {
-    }
 
-    public Set<Project> getAllProjectsForUser(Long userId) {
-        
-        
-    }
 
-    public Set<Project> getAllProjectsWithTechnology(String technology) {
-    }
 
-    public Set<Project> getAllProjectsForCurrentUser(Principal principal) {
-    }
-
-    public Set<Project> getAllProjectsWithPosition(String nameOfPosition) {
-    }
-
-    public Object applayOnProject(Long projectId, Principal principal) {
-    }
-
-    public Object confirmParticipant(Long projectId, Long participantId, Principal principal) {
+    private String technologyToString(String technology) {
+        StringBuilder technologyResult = new StringBuilder();
+        Arrays.stream(technology.split(",")).forEach(tech -> technologyResult.append(tech.trim() + " "));
+        return technologyResult.toString();
     }
 }
diff --git a/src/main/java/site/easystartup/easystartupcore/service/UserService.java b/src/main/java/site/easystartup/easystartupcore/service/UserService.java
new file mode 100644
index 0000000..b01d713
--- /dev/null
+++ b/src/main/java/site/easystartup/easystartupcore/service/UserService.java
@@ -0,0 +1,20 @@
+package site.easystartup.easystartupcore.service;
+
+import lombok.RequiredArgsConstructor;
+import org.springframework.stereotype.Service;
+import site.easystartup.easystartupcore.domain.User;
+import site.easystartup.easystartupcore.repo.UserRepo;
+
+import java.security.Principal;
+
+@Service
+@RequiredArgsConstructor
+public class UserService {
+    private final UserRepo userRepo;
+
+
+
+    public User getUserByPrincipal(Principal principal) {
+        return userRepo.findByUsername(principal.getName());
+    }
+}