Abstract: The mission of imaging is usually not considered in existing resource scheduling strategies of phased array radar, and it is required to separate a fixed part of resources for target imaging. In this paper, the concept of cognitive imaging is introduced to the radar resource scheduling strategy, and then a novel adaptive scheduling algorithm is proposed based on sparse-aperture cognitive Inverse Synthetic Aperture Radar (ISAR) imaging. The corresponding performance evaluation indicators of the proposed algorithm are also given. Based on the cognition of targets characteristics, the time resource of radar can be allocated adaptively according to the feedback information, and then the cognitive imaging of targets is achieved simultaneously during implementing tracking and searching tasks. As a result, the efficiency of the radar is improved significantly. Simulation results validate the effectiveness of the proposed algorithm.