Based on the JPDA algorithm , we proposed a multiple targets tracking algorithm m clutter: a fast JPDA algorithm by direct computatlOn the postenor probabilities IS applied to decrease the complexity ,a two stage adapt1ve target tracking filter IS used ,and anequivalent n01se covanance is introduced in this algorithm to take the interference due to neighbor targets mto account. Analysis and computer slmulation show that , the computmg load and the response t1me delay is significantly decreased.