The construction of progressive addition lenses is introduced,and the designing idea of lenses is also illustrated.The principle of designing meridional power laws for progressive addition lenses is expounded based on polynomial,and the criterion of designing meridional power laws is given out.On the basis of designing meridional power laws,the isopower contours are designed in order to determine the surfaces of progressive addition lenses.The mean surface power and the constant surface astigmatism are calculated.Three kinds of progressive addition lenses which are designed based on different meridional power laws are compared,and the lenses are manufactured and tested.It is shown that designing meridional power law is an important aspect of designing progressive addition lenses.There is much difference of the surface power,the surface astigmatism and the distortion corresponding to different meridional power laws.The rules of meridional power laws are given out to satisfy with individual demands according to the practical design and the testing results of progressive addition lenses.