Monte Carlo method is a randomly statistic method, and this method, which needs a big number of samples, has been widely applied in the vegetation canopy remote sensing because of the technological development of computer. In this paper, authors summarized the application of Monte Carlo method on the simulation of BRDF and hot spot effect in the vegetation canopy, and gave comments in detail on the parameters: LAI, LAD, G function, gap probability, free length of photon, and leaf phase function. They describe the geometrical structure of canopy.