Taking an active radar missile countermeasure as background, this paper studies the single-platform airborne electronic countermeasure (ECM) scheduling problem. In order to solve the uncertainty problem of missile seeker state observation, the partially observable Markov decision process (POMDP) theory is introduced. The elements of POMDP model are analyzed, an optimization model of ECM resources is established for the active radar homing missile, and the solution is solved by successive approximations of the reachable space under optimal policies (SARSOP). A new real-time scheduling optimization algorithm for ECM resources based on POMDP is presented, combined the output of electronic support measure (ESM) with the control strategy of ECM together. The simulation results indicate that the proposed algorithm can realize effective scheduling of ECM resources under the situation where the target state is uncertain compared with the existing approach, the radar missile will stay in seeoch state more and stable tracking state less.