Abstract: We investigated the primary productivity in the Xiangxi Bay of Three Gorges Reservoir in order to evaluate the fishery potential from 2013 to 2014. Four equations were used to calculate the fishery potential based on the primary productivity. The results demonstrated a significant spatio-temporal heterogeneity in the primary productivity in the Xiangxi Bay. Consequently the fishery potential based on the primary productivity also showed significant spatial dynamics and seasonal variation. Spatially the highest fishery potential appeared in the Gaolan branch. Temporally the highest fishery potential appeared in summer, and the seasonal order was summer spring autumn winter. The annual fishery potential calculated with the four methods above were 7.30 t/y, 10.46 t/y, 12.56 t/y and 2064.03 t/y respectively. Except for the Downing model, all other three methods generated results close to the actual fishery resources. We concluded that the phytoplanktivorous fishery resources capacity in the Xiangxi Bay was about 10 t, and the maximum sustainable yields could be 5 t. Our study provided technical support for the sustainable utilization of fisheries resource in the tributaries of the Three Gorges Reservoir.