Purpose : This research was performed to evaluate the effect on the intraocular pressureCIOP) and K-reading after cataract surgery. Method : This research was done on the cataract-operated 154 eyes, and measured both intraocular pressureOOP) and K -reading before and after surgery operation. Each of the patients was male 58(70eyes) and female73(84eye). Result : ln case of IOP in preoperative, the average value of IOP was 14.2171± 3.2264 mmHg. ln postoperative, the average value of IOP was 13.5855±3.0955 mmHg, which was lower than preoperative. And aJso statistical difference was found. In case of K-reading in preoperative, the average vaJue of K-reading was 7.6422±0.2551 mm. In postoperative, the average value of IOP was 7.6567±0.2695 mm. It showed a little deerease and no statistical diffcrcncc was fotmd. Conclusion : These results suggest that intraocular pressure(IOP) decreased after cataract surgery(p < 0.05), but we judged that age and elisease like glaucoma of each subject can influence on increase and deerease of intraocular pressureOOP) by the error. ln addition, we judged the change of K-reading was caused by incision position of operatien and type of IOL etc.