Based on the data provided by the Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR) and the relevant information on the trophic level of selected fish species from Fishbase (www.fishbase.org), this paper analyzed the temporal fluctuation on the mean trophic level (TL-i) of the finfish fishery in the Southern Ocean from 1970 to 2009. The results indicated that two stages were observed in the TL-i of the finfish fishery in the Southern Ocean, i.e., the TL-i had a decreasing trend with a lower level (3.23-3.60) from 1970 to 1991; however, the TL-i (3.82-4.02) were at a higher level from 1992 to 2009. The mean asymptotic length of catch had a similar trend to the mean trophic level. The fishinginbalance (FiB) index was the highest in 1970 and maintained at a stable level after 1997.