GECAM is a dedicated all-sky monitor with a very large instantaneous field of view in the X-ray and soft gamma-ray band. The primary science objectives are:

(1) to monitor and characterize the high energy counterparts of gravitational waves (GWs), to reveal the underlying physics of neutron stars, black holes and binary merger.

(2) to monitor and characterize the high energy counterparts of fast radio burst (FRBs), to reveal the origin and emission mechanism.

(3) to discover various types of gamma-ray bursts (GRBs) and soft gamma-ray repeaters (SGRs), to deepen our understanding of their burst physics.