Abstract: In order to improve the purity and production of C-phycocyanin( C-PC) in Synechococcus sp.PCC 7002,extraction and purification of C-phycocyanin in Synechococcus sp.PCC 7002 was investigated. Tissue-trituration method,cycle of freezing and thawing method and ultrasonic method were applied and compared to the effection on the purity and production of C-phycocyanin. Response surface methodology( RSM) was used to optimize the best cell- disruption conditions. Futher purification was performed by means of ammonium sulphate precipitation and hydroxyapatite( HA) chromatography. The purified protein was examined through SDS-PAGE. The results showed that cycle of freezing and thawing method was the optimal cell-disruption method by the RSM experiment,the best cell-disruption conditions were that the concentration of bacteria was 3.53 mg / m L,the cycles of freezing and thawing was 6 times,the thawing temperature was 37 ℃,the best concentration of salting out was55% ammonium sulfate,the purity of C-phycocyanin reached 3.79 through hydroxyapatite chromatography. The optimal method of extraction and purification of phycocyanin from Synechococcus sp.PCC 7002 was achieved.