Abstract: There are great differences among the target-s radar cross section(RCS) in its different detect angle territory. Five different models about the partition of important radar detect territories were presented. In the computer simulation platform, it adopted the five different models to part the important detect territories according to the characteristics of scattering around the target. Calculating the detect probabilities according to the average RCS from the different five models. The average tolerance of detect probabilities between the results of five models and exact detect probabilities are 13.66%, 12.35%, 6.6%, 5.07% and 2.4%.The differences between the tolerances indicate the detect probabilities from the last two models about the detect territory partition are more accurate. They can reflect the real changes of detect probabilities in the dynamic process of the radar detects the target. The last two models about the partition of important radar detect territories in the computer simulation platform can save the computer storage by using five or eight RCS to instead of lots of RCS. It can increase the computer speed.