Abstract: In any latitude within the polar circle,the aceuracy of the formyla in the paper used for calculating the total amount of the astronomical insolation is similar to Milankovitch's formula,in the latiudes outside the polar circle the formula in the paper has a ligh aceuracy,but Milankovitch's formula is not fit for calculation because of its high erroe.Accordingly,the influence of the earth's orbital parameters on the radiation term in the climatic change is also discussed.The result is shown that the characteristics of the insolation distribution in the last glacial and interglacial periods over the Northern Hemisphere correspend to many of new facts in the geological evidence in the present time.Thus,it is possible to estimate the radiation conditions in future change of the climate.