China has embarked on the promotion of offshore solar photovoltaic (PV) development along its coastal regions in pursuit of carbon neutrality. An evaluation of the inherent features and exploitative potential of offshore solar PV resource stands as a pivotal measure to the development and utilization of China's offshore solar PV resource. To this end, the tripartite objectives of this study unfold as follows: i) investigating offshore solar energy features, which include spatial distribution of PV resource and its monthly and hourly variations, along with an examination of climate change impacts; ii) analyzing ocean conditions that exert an influence on offshore solar PV farms; and iii) proposing criteria for assessing the suitability of offshore solar PV development, considering both resource characteristics and ocean conditions, thereby identifying the most promising areas for forthcoming offshore PV projects. The findings reveal that the South China Sea has the richest offshore solar PV resource and the least intra-annual fluctuation, despite challenging ocean conditions. Over the past 60 years, there has been a slight decrease in the solar resources in the majority of the South China Sea, in contrast to a marginal upswing observed in the Yellow Sea and Bohai Sea. Recommendations for future offshore solar PV development suggest considering the southwest waters of Hainan Island, where the proportion of annual PV power generation to power consumption of the island in 2022 is nearly 225%.