diff --git a/sources/reactphysics3d/engine/PhysicsWorld.cpp b/sources/reactphysics3d/engine/PhysicsWorld.cpp
index ba3a5550..0be49688 100644
--- a/sources/reactphysics3d/engine/PhysicsWorld.cpp
+++ b/sources/reactphysics3d/engine/PhysicsWorld.cpp
@@ -29,13 +29,6 @@ PhysicsWorld::PhysicsWorld(const Vector3D& gravity)
 
 }
 
-// Copy-constructor
-PhysicsWorld::PhysicsWorld(const PhysicsWorld& world) {
-    bodyList = world.bodyList;
-    gravity = world.gravity;
-    isGravityOn = world.isGravityOn;
-}
-
 // Destructor
 PhysicsWorld::~PhysicsWorld() {
 
@@ -87,3 +80,35 @@ void PhysicsWorld::removeBody(Body const* const body) throw(std::invalid_argumen
         throw std::invalid_argument("Exception in PhysicsWorld::removeBody() : The argument pointer cannot be NULL");
     }
 }
+
+// Add a constraint into the physics world
+void PhysicsWorld::addConstraint(Constraint* constraint) throw(std::invalid_argument) {
+    assert(constraint != 0);
+    constraintList.push_back(constraint);
+}
+
+// Remove a constraint
+void PhysicsWorld::removeConstraint(Constraint* constraint) throw(std::invalid_argument) {
+    // TODO : Implement this method
+}
+
+// Remove all collision contacts constraints
+void PhysicsWorld::removeAllContactConstraints() {
+    // For all constraints
+    for (std::vector<Constraint*>::iterator it = constraintList.begin(); it != constraintList.end(); ) {
+
+        // Try a downcasting
+        Contact* contact = dynamic_cast<Contact*>(*it);
+
+        // If the constraint is a contact
+        if (contact != 0) {
+            // Delete the  contact
+            delete (*it);
+            it = constraintList.erase(it);
+        }
+        else {
+            ++it;
+        }
+    }
+}
+
diff --git a/sources/reactphysics3d/engine/PhysicsWorld.h b/sources/reactphysics3d/engine/PhysicsWorld.h
index 6ecb15ff..664e9392 100644
--- a/sources/reactphysics3d/engine/PhysicsWorld.h
+++ b/sources/reactphysics3d/engine/PhysicsWorld.h
@@ -31,20 +31,20 @@ namespace reactphysics3d {
 
 /*  -------------------------------------------------------------------
     Class PhysicsWorld :
-        This is an (abstract) class that represents the world of the
-        physics engine. A physics world contains all the bodies of the physics
+        This class represents the world of the
+        physics engine. The physics world contains all the bodies of the physics
         engine.
     -------------------------------------------------------------------
 */
 class PhysicsWorld {
     protected :
         std::vector<Body*> bodyList;                // list that contains all bodies of the physics world
+        std::vector<Constraint*> constraintList;    // List that contains all the current constraints
         Vector3D gravity;                           // Gravity vector of the world
         bool isGravityOn;                           // True if the gravity force is on
 
     public :
         PhysicsWorld(const Vector3D& gravity);      // Constructor
-        PhysicsWorld(const PhysicsWorld&);          // Copy-constructor
         virtual ~PhysicsWorld();                    // Destructor
 
         void addBody(Body* body) throw(std::invalid_argument);                  // Add a body to the physics world
@@ -54,6 +54,11 @@ class PhysicsWorld {
         void setIsGratityOn(bool isGravityOn);                                  // Set the isGravityOn attribute
         std::vector<Body*>::const_iterator getBodyListStartIterator() const;    // Return a start iterator on the body list
         std::vector<Body*>::const_iterator getBodyListEndIterator() const;      // Return a end iterator on the body list
+        void addConstraint(Constraint* constraint) throw(std::invalid_argument);            // Add a constraint
+        void removeConstraint(Constraint* constraint) throw(std::invalid_argument);         // Remove a constraint
+        void removeAllContactConstraints();                                                 // Remove all collision contacts constraints
+        std::vector<Constraint*>::const_iterator getConstraintListStartIterator() const;    // Return a start iterator on the constraint list
+        std::vector<Constraint*>::const_iterator getConstraintListEndIterator() const;      // Return a end iterator on the constraint list
 };
 
 // --- Inline functions --- //