Comparing solutions of different pH （5.5 - 9.5） and different salinity to develop suitable basic solution for spermatozoa cryopreservation of pearl oyster Pinctada martensii, we chose the basic solution, which could inhibit the activation and had less influence on the physiological characteristics （such as activity, life span and fertilizing capability） of the spermatozoa, and adopted dimethyl sulfoxide （DMSO） as antifreeze to compound diluents for protecting the spermatozoa. After combination of natural seawater with DMSO （10%） and seminal fluid at the ratios of 1 ： 10 and 1：20, the specimens were transferred into LN2 by 4 temperaturelowering processes. The conclusion showed that cryopreservation processes were effective in which the samples were pre-frozen in 0- 8 ℃ within 30 minutes, swung at 15 cm above for 5 min and then at 5 cm above LN2 for 10min, transferred them into LN2 for prolonging period （24 h, 48 h and 5 months ）, and then thawed them with water at 35-40 ℃, the survival rate of spermatozoa could exceed 60% when activated with 0.25‰ ammonia seawater and the fertilization rate could reach 80%.