HY-2: Basic, inertial and conical radar search (improved to SY-1), 1970.
HY-2A: IR-guidance variant. Developed during the 1970s and in 1980, it did not enter service despite certification in 1982. It was the equivalent of the P-22.
HY-2A-II: An improved variant of the HY-2A with an improved IR sensor, it entered service in 1988. It was also available for export.
HY-2B: Fitted with monopulse-search radar to improve accuracy and reliability, it was test-fired, scoring five hits out of six and entered service two years later in 1984. The YB-2B-II had another radar search system, entering service in 1989. These two missiles were capable of flying at an altitude of 20–50 m, so the overall capabilities (altitude, range, reliability, Electronic Counter Counter Measures (ECCM) were greatly superior.
