In this paper, three main indices of multitarget tracking in random set framework were compared，including Circular Position Error Probability (CPEP) distance, Wasserstein distance and Optimal Subpattern Assignment (OSPA) distance. Their characters, conditions, pros and cons were first investigated. Besides, the existing formula for the CPEP distance, which may cause confusion, was modified. The result shows that the CPEP distance can be used to evaluate target lost. Compared with the OSPA distance, the Wasserstein distance is easy but may be intuitively inconsistent in some cases, while the OSPA distance is more reasonable. Nevertheless, it needs to select the level parameter and this is subjective. Finally, two experiments are proposed to validate these indices.