Abstract: The production of A. Longicornis in Lake Biandantang was calculated by three methods. The results are: 2.088g穖-2穉-1 of wet weight with shell or 0.103g穖-2穉-1 of dry weight shell-free by size-frequency method; 2.122g穖-2穉-1 of wet weight with shell or 0.1061g穖-2穉-1 of dry weight shell-free by Allen curve method; 2.273g穖-2穉-1 of wet weight with shell or 0.1137g穖-2穉-1 of dry weight shell-free by instantaneous growth method. The corresponding P/B ratio are 4.3, 4.3, 4.0, respectively. Therefore, the results by the three methods are coincided with one another, which might be of great significance in estimation of macro-invertebrate production.