To analyse the reasons of low vision after phacoemulsification with intraocular lens (IOL) implantation. METHODS:Totally 323 cases (368 eyes) who had received phacoemulsification with IOL implantation were followed up and observed on their visions and corrected visual acuities one month after operation,then the patients whose corrected visual acuities were less than 0.3 were examined completely to find the causes of low vision. RESULTS:The incidences of postoperative low vision were 51.90％,27.99％ and 12.23％ respectively for 1st，7th and 30th day after operation．The incidence of postoperative low vision of the first month after operation was similar to that reported in the previous literature (13.21％)． CONCLUSION: Phacoemulsification with IOL implantation is one of the effective methods for curing cataract. The key factor affecting vision restoration is original ocular diseases．