What was this helicopter photographed on a Chinese aircraft carrier?
Can't say for sure, but the size and shape (as far as can be determined from the picture) seems to match the Aerospatiale Super Frelon, which is built under license in China and is in use with the Chinese navy for shipboard operations under designation Z-8.

The image is of poor enough quality that a more precise determination isn't feasible, but the size and shape match the type and the type is in Chinese service (unlike similarly sized helicopters).