The structures of Nylon-1010 with different draw ratios have been investigated by using Small-AngleX-ray Scattering(SAXS).It is shown that by using a simple geometrical construction the following structureparameters can be directly derived from the correlation function,the long period(L),the thickness of thecrystal amorphous interphase(dtr),the lamellar thickness(do),the“invariant”(Q),the specific inner surface(Os),and the electron density difference between the core of the crystallites and the amorphous matrix(η;-η;)。