Clock pulse is always generated via crystal vibrator. But in some special conditions that clock pulse circuit is in malfunction, or clock frequency is not high enough, some ingenious implement ways of generating clock pulse in FPGA can solve the problem. In this paper, three methods of generating pulses in FPGA are put forward. The pulses generating are mainly based on short response time of the FPGA logic cells, so the frequency of the pulses is high. Analysis and experiments show that pulses can be generated via FPGA itself other than external clock circuit, and these implement ways of generating clock pulse in FPGA are feasible.