Abstract: There are limited drilling data and few development layers in Block C of East China Sea, and the development effect of the main reservoir is not ideal. The application of reservoir geophysical technology in the development evaluation and adjustment of oil and gas reservoirs in Block C of East China Sea is aimed at improving the overall development effect of the block. For the new strata, reservoir description and potential prediction are carried out by means of geophysical techniques such as trap description and gas prediction, so as to realize the increase of reserves and production of new layers and the efficient production of low amplitude oil and gas reservoirs with low bottom water. In response to the low recovery rate, low production rate, and high water content of the main reservoir, geophysical techniques such as seismic forward modeling, seismic facies characteristics and seismic attributes were used to carry out fine reservoir analysis, guiding distribution prediction of remaining oil and gas and adjusting potential research. Reservoir geophysical technology plays a good role in the development evaluation and reservoir adjustment of Block C in East China Sea, which can provide reference for development of other similar blocks.