Abstract: This paper presents a map animation method to visualize the spatial uncertainty based on Monte Carlo simulation and particle system model.The method can be used in the uncertainty visualization of geographic boundary location and attribute distribution inside polygon region.The algorithm is developed on the basis of pixel random movement including stages of birth, action and death.The description of each pixel in rastermap involves position, movement speed, movement direction, color brightness and life span. The randomization change of these variables enables reader to feel that the attribute distribution is uncertainty within a polygon.Through Monte Carlo simulation method, the number of different color pixels can be controlled consistently with the proportion of corresponding attribute class.