Ark shell (Anadara broughtonii) is one of the most important and widely cultured commercial bivalves in our country. In order to avoid over cultivation, it is necessary to find a way to estimate the carrying capacity of certain water areas. The study on feeding physiology and filter feeding ability of ark shell may help to understand the carrying capacity. In this study, we investigated the filter-feeding effect of ark shell on Cylindrotheca fusiformi in dark condition, and the filter-feeding ability, functional reactive type and the filter-feeding effect of ark shell on algae were analyzed. Data were analyzed by using the one–way ANOVA and chi-square test. All analyses were performed with a significance level of P < 0.05. The results showed that in the condition of 20℃, the mean filter feeding rate of the juveniles significantly increased with the increasing algae concentration (P < 0.05) (Fig.1); meanwhile, the filter feeding rate in 0 - 4h was much higher than others in each concentration groups (Table 1). The pattern of function response was classified as Holling-Ⅱ type, and the fitted Holling disc equation was at 20℃ (Fig.3). The attacking coefficient was 1.019 5 at the same time. Based on this disc equation, the maximum feeding amount of each ark shell (shell length 30 - 35 mm) was 500 (× 107 cells/L) per day. The filter feeding rate (Fig.2) and the attacking coefficient (Table 2) tended to increase first and then declined in the range of 10 - 25℃ and reached peak level at 20℃, supporting that 20℃ was the most optimum feeding temperature. Besides, a strong intraspecific mutual interference was found in the filter-feeding activity of ark shell. Both of the average filter-feeding quantities and the filter-feeding efficiency declined with the increasing ark shell density, thus the power function equation for the density to C. fusiformisid was (Fig.4). In addition, the associated response equation was developed to connect the density of ark shell and the concentration of C. fusiformis (Table 3). The results suggest that the ark shell possess a strong potential filter-feeding capacity at 20℃，and there be existed an obvious characteristic of “negative density effect” between the average filter-feeding quantities / the filter-feeding efficiency and the density of juveniles.