Gravitational wave high-energy Electromagnetic Counterpart All-sky Monitor (GECAM) is a constellation composed of four x-ray/gamma-ray monitors on different spacecrafts, dedicated to observe high energy transients, including GRBs (especially those associated with GW and HEN) and SGRs (especially those associated with FRB). Thanks to its novel design, GECAM has accurately detected some interesting events, including the extremely bright GRBs (GRB 221009A and GRB 230307A) and mangetar bursts associated with radio bursts. In this talk I will give a brief overview of GECAM and observation results.