Gamma Ray Bursts (GRBs) are mainly divided into two classes based on typical duration of the initial gamma-ray emission. One of the most discussed formation channels of short GRBs is the coalescence of binary compact objects under energy and  angular momentum loss to gravitational waves. The merger product is debated to be either a black hole or a rapidly spinning magnetar. Progenitor models are still explored to accommodate continued central engine activity in short GRBs. Gravitational wave observations of short GRBs in imminent future is expected to provide crucial complementary information to their nature. I will review the current status of electromagnetic observations and theoretical models of short GRB central engine and the implications of future GW observations.