The urbanization of some developed countries, such as America, Britain, Japan and Germany, indicates that the urbanization process shows significant S-type characteristics, and Gompertz curve is a good choice to simulate them. Combining with some of Gompertz‘s characters such as monotonicity, periodicity, and having an inflection point, this article tries to apply Gompertz curve fitting to the urbanization process of Shandong province. The results show that the urbanization process of Shandong province can be divided into four stages by 1975, 2003, and 2030, and 2003 is a turning point. After 2003, the urbanization level is still rising, but growth rate began to decline. 85.58% is the saturation value of urbanization, and after reaching this value, urbanization rate will be difficult to grow. Future urbanization in Shandong province must conform to this rule, and it is more important to pay attention to the quality of urbanization rather than the speed of growth.