By using the city parks data grounded on Beijing green space census, based on ArcGIS and Fragstats and landscape metrics, this paper conducted a quantitative analysis of the variation of overall, zoning and gradient pattern of Beijing city parks' spatial pattern from 2000 to 2010, and revealed the driving factors of the changes. Some conclusions can be drawn as follows: (1) In the overall pattern, the number and area of city parks have increased substantially, especially those of special parks and community parks. The distribution of comprehensive parks and special parks has an absolute advantage. The contagion of parks has been changing from "center high peripheral low" to "center high peripheral improving high". The aggression has changed from center aggregation to peripheral multi-dimensional aggregation. (2) In the division pattern, all types of city parks’ERI varied significantly in sectors, rings and administrative districts. The variation of the curve of eveness rate is complex. Also, all kinds of city parks are distributed unevenly in different districts. (3) The analysis of eight-direction gradient pattern indicated that the distribution of Beijing city parks was unbalanced and changed significantly. Large parks were mainly distributed in the "north" and "northwest" directions. The areas and number of parks in the west, east, northwest and northeast were larger, and the increasing rate were comparatively high. (4) Events, green policy, rapid urbanization and residents’increasing environment demands, which can contribute to growing number, areas of parks and the unbalance of their space distribution, are the four major driving factors of the variation of spatial pattern of Beijing city parks in recent 10 years. This paper provides valuable references for the future construction and optimization of the distribution of Beijing city parks.