Platycephalus in Chinese sea area has a high commercial value. However, there were mis-identifications in previous records. In this study, we fully distinguished and diagnosed all five species, Platycephalus indicus, P. cultellatus, Platycephalus sp., Platycephalus sp. 1 and Platycephalus sp. 2. The results revealed that P. cultellatus was overlooked by previous ichthyologists. Platycephalus sp. 1 was misidentified as P. indicus in reality, and Platycephalus sp. 2 only existed in the seas of Japan. Furthermore, morphological, especially phylogenetic analysis indicated that Platycephalus sp. from South China Sea differs from all former known species, which might be a new species. We identified all Platycephalus species in China seas for the first time, which will contribute to local species identification, biodiversity conservation and sustainable exploitation of Platycephalus species.