Abstract: Based on the survey data from September to October in 2012, we analyzed the fishing ground and catch composition of large-scale light falling-net fishery in the central and southern South China Sea in autumn. According to the index of relative importance ( IRI) , Sthenoteuthis oualaniensis and Katsuwonus pelamis were the dominant species; Euthynnus affinis, Auxis thazard and A. rochei were the major species; Decapterus macarellus and D. macrosoma and so on were the common species. Generally, S. oualaniensis, tuna species and round scad were the main species which accounted for 48.35% , 48.33% and 0.98% of the total catches, respectively, and small tunas occupied 47.77% of the total. The catch rate varied significantly among different fishing grounds, which was 411.47 kgh-1 in Xisha and Zhongsha waters but only 25.66 kgh-1 in Nansha waters. The central fishing ground was located in waters of 1230N～1530N, 11030E～11500E. The results indicate that autumn is a very good fishing season for light falling-net in offshore waters. Besides, S. oualaniensis and larger tuna species, small tuna species and round scad should be further studied.