Fan Ji (反击, meaning counter strike) anti-ballistic missile (FJ ABM) was the missile used in the HQ-81 ABM system (ABMS), which was the land based component of 640-1 ABMS project, which in turn, was part of the Chinese 640 ABMS project in the 1960s. Although the project was cancelled in Mar 1980's, the experience gained had helped China in later ABMS development.