In this paper, the monthly spatial dynamics of vegetation LAI during 2010-2012 in Beijing, China, were estimated based on the MODISLAI data and the functional classification of vegetation. The yearly dynamics and differences of vegetation LAI of various vegetations were also investigated based on Geographic Information System and Timesat software. The results suggested that the higher values of monthly vegetation LAI during 2010-2012 mainly occurred in the forest zones of the northwest and northeast mountains as well as the northern areas of Huairou District. The spatially descended trend was found from the northeast mountains to southwest area and then to the central Beijing City. Additionally, the changes of annual average LAI of various vegetations were not obvious during the study period. The annual average of LAI varied in the ranges of 1.45-1.50, 1.24-1.27, 0.90-0.92, and 0.48-0.51 for coniferous forest, broadleaf forest, grassland, and crop, respectively. The results of SavitzkyGolay filtering indicated that the growth trajectories of coniferous forest, broadleaf forest, grass, and crop could be reflected by the inter-monthly variation of LAI.