The MiG-25 was designed to counter high-flying threats. The MiG-31 was the result of the demand to counter low-level threats, such as the B-1B and cruise missiles. The Ye-155MP was the prototype of the design and first flew on 16 September 1975. The Ye-155MP was a converted MiG-25MP.
Production started in the year 1979. In 1982 the NATO reporting name 'Foxhound' was made public. In early 1983 replacement of MiG-23s, Tu-28s, Su-15s in the air defense role began. By 1987 over 150 MiG-31s were deployed accross the Soviet Union, especially in the west and far east. Reportedly about 500 aircraft were built.
Reportedly a contract with China was signed in 1992 for 24 MiG-31 interceptors. The plan included a newly set-up factory in Shenyang and were expected to enter service in 2000. At some point it was expected that at least 200 MiG-31s would be deployed by 2010. The contract was either cancelled or was never signed. Instead China opted for the Su-27/30 Flanker (J-11) as their long range interceptor.
Ye-155MP converted MiG-25MP prototype