Abstract：In this study，we used the nervous neurosis virus ( NNV ) test standard of Office International Des Epizooties (OIE) to detect the viral nervous necrosis of Epinephelus coioides collected from southern Fujian. All the six samples were detected to be infected with NNV. The positive clones were separately sequenced from both forward and reverse directions with vector primers，and the sequences were used to construct the phylogenetic trees. The virus particles were isolated and purified by PEG method. All the sequence information of positive clones was utilized to analyze the selection pressure of viral coat protein gene. The results showed that the collected six samples were infected with RGNNV，indicating that the infectious NNV of grouper was mainly RGNNV in southern Fujian. The vims was isolated and purified to obtain a kind oi icosahedral vims paricles with a diameter of 25~28 nm. Molecular evolution analysis showed that the NNV coat protein gene experienced the purification selection，indicating that the virus retained very low genetic variation.