OBJECTIVE To develop the METHOD for the determination of cefoperazone sodium(CPZ) and sulbactam sodium(SBT) for injection and to measure the degradates of the products made by solvent crystallization and lyophilization method.METHOD ODS column was used to assay cefoperazone and sulbactam simultaneously.Triethylamine glacial acetic acid solution -acetonitrile-l mol·L_-1 acetic acid-water(20∶140∶5∶835) was used as the mobile phase,with UV detection at 210 nm.RESULTS The components had good linear relation and their average recoveries were 99.86% for CPZ and 100.44% for SBT respectively.S isomer in CPZ,T-1551B and other related substances were seperated well.The quality character of CPZ made by solvent crystallization or lyophilization method was also studied.The latter was more hygroscopic than the former;and more degradation products were formed than the former at higher temperature.CONCLUSION The determination method was accurate and reliable.The quality of the product made by solvent crystallization method is better than that of the product made by lyophilization method.