Antigenic analysis of 10 strains of Coxsackievirus type A 24 (CA24) was carried out by monoclonal antibodies (McAbs) prepared with a China isolate of Coxsackievirus A 24 variant (CA24v).8 McAbs which were positive in indirect immunofluorescent test reacted to 9 CA 24 v detected. Of them, 4 McAbs could react to both CA 24v and CA 24 prototype (Joseph strain),and the others did not react to CA 24 prototype. 5 McAbs possessing virus-neutralizing activity did not neutralized CA 24 prototype (Joseph strain)and only one of them could neutralize EH 24/70 strain weakly, three of them neutralize 2 isolate from Japan in 1985-86 (J140/85 and J 60/86) and one isolate Fujian of China in 1986. However, all 5 McAbs above could neutralize isolate from Henan and Shanghai of China in 1986 as well as Beijing, Liaoning and Fujian of China in 1988.