This article studies the impact of Western astronomy on annual Almanacs during the late Ming and early Qing in terms of investigating the computation and its accuracy of the time that apparent sun enters one of the twelve stations of the zodiac recorded in the annual almanacs during the early and middle Qing period. Different with the traditional method of using linear interpolation to compute the solar position, the new method was a deductive geometrical system. In the new system, the solar theory has the form of a geometrical model, the parameters of which are deduced from observations. The practical computations and predictions of the solar position can be made from solar handy tables which were derived from the solar model. The data of the time of apparent sun enters one of the twelve signs in early Qing annual civil calendar were computed from Xiyang Xinfa Lishu西洋新法历书 (Western Treatises on Calendrical Astronomy According to the New Method) in which the solar model is eccentric. The error of the data record in early Qing period remained large in general with respect to the data based on the computation by using Sky-map software. As the accuracy of computation of solar position did not increase that it attached attention of Kangxi emperor, the emperor at last determined to open the Hall of Cultivation( Mengyangzhai，蒙养斋) to compile Yuzhi Lixiang Kaocheng 御制历象考成（Thorough Investigation of Calendrical Astronomy Imperially Composed）. The scholar-officials in the studio constructed a double epicycle solar model which were put into Yuzhi Lixiang Kaocheng on the basis of their own observations by using the gnomon to measure and calculate the solar shadow. The data recorded in the annual civil calendar from the fourth year of Yongzheng reign period were computed according to Yuzhi Lixiang Kaocheng. But as their observations remains an error, the accuracy of the practical computations that the time of apparent sun enters one of the twelve stations in civil calendar in which based upon the solar model did not improve with respect to the former calendar.