The natural history of corneal astigmatism in 118 eyes following extracapsular cataract extraction and PC IOL implantation demonstrated that the average surgery induced with-the-rule astigmatism of 3.37D one week after the operation declined at a rate of 0.60, 0.63 and 0.39D during the 1st, 2nd and 3rd months respectively, indicating that the with-the-rule astigmatism of 2.00-3.00D would be corrected spontaneously to the normal or physiological status. The relationship between the changes in astigmatism and postoperative vision and the intraocular pressure was discussed.