Based on analyses about the latest U.S statistical data and charts, author of this paper deduces the empirical equation of the impeller's geometric parameters, which aims at improving the efficiency of the low special speed centrifugal pump, and shortening the designing period. The development of the special method of impeller's meridional drawing, especially the checking method and procedure's formation of F-L curve, on the base of mathematics analyze, makes the impeller's meridional drawing ...