AIM:To investigate the effect of various parameters on corneal endothelial cells in cataract surgery. METHODS:All 55 cases of cataract patients were randomly selected by lens nuclear grade. With cataract phacoemulsification and intraocular lens implantation, intraoperative ultrasound energy, time and the cumulative releases of energy (CDE) were recorded. Before and 1 week after surgery the central corneal endothelial cell density of the region, the proportion of hexagonal cells were measured. Stepwise regression analysis of the data using software SPSS 17.0 were processed. Affecting factors on the decline of corneal endothelial cell density and hexagonal cell proportion were analysed to identify factors that affect the corneal endothelial cell damage. RESULTS:Before and 1 week after surgery, corneal endothelial cell density was 2685.78±413.39/mm² and 2524.39±557.80/mm², hexagonal cells proportion was 53.04±9.68% and 49.82±9.39%. Compared with the preoperative,postoperative corneal endothelial cell density was significantly decreased and the proportion of hexagonal cells decreased. Statistics found that the strongest influence factor on the corneal endothelial cell was nuclear hardness (P=0.000), followed by the cumulative release of phaco-emulsification energy (P=0.041) and phacoemulsification time (P=0.046). According to statistical analysis they were statistically significant (P<0.05). CONCLUSION:The degree of lens nuclear grade, phacoemulsification ultrasound energy and the length of phacoemulsification time are major risk factors on the corneal endothelial cell damage. Therefore, improving surgical techniques, reducing intraoperative phaco-emulsification time, reducing the release of invalid ultrasonic energy can effectively reduce the corneal endothelial cell damage.