This tutorial on assembly design of a turbine rotor with eight blades and casing helps the engineering students and working professionals to know completely the procedure involved in the CATIA assembly design of a turbine rotor with eight blades and a casing. In the process of learning this assembly , the viewers will know how to start the assembly design, how to bring the components of the assembly and also they will know how to rename the parts going into properties. They will also learn about moving the individual components either by moving components with existing positioning or by using compass. In the process of assembling components they will know how to fix a component which is not moving, also learn about coincidence constraint and offset constraint. By doing the above procedures, the assembly will be ready for kinematics part and corresponding animation.