Abstract: From July 2009 to May 2010, a seasonal survey was conducted on the macrobenthos in the tidal flat of Tianhe Town in Wenzhou City, and the secondary productivity of the macrobenthos was calculated, based on the macrobenthic biomass and energy and by using the Brey’s empirical formula. The mean biomass, energy, annual ashfree dry mass (AFDM), annual secondary productivity, and annual P/B value of the macrobenthos were 7.2264±0.8766 g·m^-2, 44360±4373 J·m^-2, 6.51±0.79 g (AFDW)·m^-2, 7.71±0.96 g (AFDW)·m^-2·a^-1, and 1.18±0.07, respectively. The macrobenthic secondary productivity was the highest in middle tidal flat, followed by in high tidal flat, and the lowest in low tidal flat. With the seasonal variation of tidal flat, the biomass and energy of the macrobenthos had the same variation trend in high and low tidal flats, but not in middle tidal flat. Season and tidal flat were the most important factors affecting the spatiotemporal variations of the macrobenthic secondary productivity. Because of the individual action and the interaction of these two factors, the macrobenthic secondary productivity in the Tianhe tidal flat showed complex patterns.