Time modulated array (TMA) suffers from relatively unstable instantaneous gain due to the variation in both efficiency of feeding network and directivity as different number switches are in off state. In this letter, a TMA design using reconfigurable power divide/combiner (RPDC) is proposed to improve the stability of instantaneous gain. Since the power, which is always wasted in the absorbed switches during off state, can be reused by RPDC, the fluctuation of instantaneous efficiency of feeding network can be avoided, and the corresponding stability of instantaneous gain can be improved. According to the work characteristic of RPDC, the genetic algorithm is adopted to optimize the pulse sequences for controlling both the instantaneous gain and average radiation pattern. Representative results are presented to verify the effectiveness of the proposed design, and are also in comparison with previous works.