Russia helped China with Mig 15 and Mig 17, but later , due to the worsen of the relationship, send Mig 21 factory to India.  However, with the learning from Russia,  China developed J7, and and later , JF 17. and then based on the experiences learn, China developed J 10, J 16, J 15, and J 20, still using H6 bomber which based on Tu 95,