The shell weight and abundance of planktonic foraminifera, together with seawater parameters, collected from area off the Southern Taiwan were analyzed in this study. Plankton tows were conducted between April 2006 and December 2011 at water depths of 50, 100, 150, and 200 m. In addition, five sediment trap moorings and one box core were sampled at the same area. Globigerinoides sacculifer was picked for counting numbers and measuring weight from towed samples and core sediments. For seawater samples, dissolved inorganic carbon was analyzed. The age model of sediment core was determined based on the excess lead-210. The seasonal variation of planktonic foraminifera abundance is not obvious in the Gao-ping submarine canyon regime. The shell abundance decreases as the depth increases. Furthermore, the relationship between shell abundance and lunar cycle can be observed from the sediment trap moorings. Shell abundance reaches its maximum before full moon. The sea surface is dominated with larger shells at night than daytime. Shell abundance and size are closely related with the optima growth environmental parameters than anything else. The foraminiferal shell weight is not so different between winter, summer, and autumn. But in spring the shell weight is the lightest among all. Based on the foraminiferal shell weight and the corresponding seawater carbonate ion concentration obtained from this study, it is not easy to explain the relationship between both. Shell weight in downcore record was lighter after A.D. 1890, which probably was caused by the acidification of seawater resulted from the increase of CO2 in the atmosphere.