Abstract: A present status of the diagnostics in EAST is presented. As a very important step of the EAST project, tens of diagnostics were employed for operation and protection, plasma control and physics analysis to accommodate requirement for the study on plasma performance in EAST with upgraded RF power up to 4 MW (both LHCD and ICRF) in the forthcoming years. Recently, new diagnostics are set up to provide several profiles of key plasma parameters for the further evaluation and better understanding of the plasma performance and physics in EAST, including a 25-channel Thomson scattering system for density and electron temperature, a metal bolometry for radiated power, an X-ray crystal spectroscopy for both ion and electron temperatures and plasma rotation velocity, etc. It is expected that these diagnostics would play an important role in data analysis and interpretation combined with integrated modeling.