The performance of the missiles is determined mostly by the accuracy and dispersion of the random fall points. In small samples case, it is difficult to assess respectively the accuracy and dispersion. The integration assessment approach adopting probability circle method is proposed. The performance is accepted when the number which fall into the probability circle is larger than or equal to the number predetermined, otherwise it is rejected. The producer's risk and consumer's risk are also given. Finally, the simulation shows that the approach proposed in this paper is available. Probability circle method is simple and easy for practical applications.