AIM:To study the changes anterior chamber angle(ACA),corneal thickness and depth of anterior chamber after phacoemulsification and foldable intraocular lens(IOL) implantation by ultrasound biomicroscopy. ·METHODS:Small-incision phacoemulsification and foldable IOL implantation were performed in 20 eyes of 20 senior patients,and the changes of corneal thickness,ACA and anterior chamber depth were determined quantitatively by ultrasound biomicroscopy before and one week after the surgery. ·RESULTS:In all patients,the anterior chamber angle was widened significantly at one week after surgery.The measurements of AOD500(angle-opening distance at 500μm from the scleral spur) and ACA increased significantly after the operation.The mean post/operative corneal thickness was significant increased. A significant negative correlation existed between preoperative and postoperative data(P<0.01). ·CONCLUSION:Small-incision cataract surgery increases the thickness of corneal,deepens the anterior chamber and widens the ACA in senior patients.