Abstract: A gastrocotylid monogenean species Pseudaxinoides australis Lebedev, 1968 was found on the gills of a marine fish, Decapterus russelli, from Shanwei city, Guangdong Province. The specimens are basically consistent with the original description of Lebedev, 1968 expect for the number of clamps and testis, the length of anchors and genital spines. This is the first time the species Pseudaxinoides australis Lebedev, 1968 recorded in China, and the fish Decapterus russelli is a new host. The specimens are deposited in the Lab of Fish Parasitology, College of Life Sciences, South China Normal University .