A conventional multi-channel pulse amplitude analyzer acquires single energy spectrum,but provides no information on its tendency with time.To address the limitation,we propose a scheme of time-sharing multichannel pulse amplitude analyzer(TSMCA).A dual-port random access memory is divided into two storage spaces,one for current energy spectrum data acquisition and another for previous energy spectrum data storage.The two tasks can be performed simultaneously,and the time-related variation tendency of energy spectrum can be obtained.A prototype system of TSMCA is designed.It performs nicely,with maximum channel number of 4096 in capacity of 2~(32)/Ch,minimal time-sharing slice of 25 ms,the differential nonlinearity of <1.5%,and the integral nonlinearity of <0.3%. A conventional multi-channel pulse amplitude analyzer acquires single energy spectrum, but provides no information on its tendency with time. To address the limitation, we propose a scheme of time-sharing multichannel pulse amplitude analyzer (TSMCA). A dual-port random access memory is divided into two storage spaces, one for current energy spectrum data acquisition and another for previous energy spectrum data storage. two tasks can be performed simultaneously, and the time-related variation tendency of energy spectrum can be obtained. A prototype system of TSMCA is designed to perform nicely, with a maximum channel number of 4096 in capacity of 2~32 / Ch, minimal time-sharing slice of 25 ms, the differential nonlinearity of <1.5%, and the integral nonlinearity of <0.3% .