Energy flux and regulating factors were examined over an entire year (2010) in mangrove wetland in Zhangjiang estuary. The results show that the seasonal changes of the energy fluxes and Bowen ratio (β) were greatly affected by net radiation. The opposite seasonal dominant of the LE and Hs resulted in significant seasonal changes in Bowen ratio ( ).During winter season,  could reach a maximum of 1.52.While enter summer days, β fluctuated from 0.37 to 1.0. Tidal activity had different effects on energy budget in different seasons. During tidal flooding days, β was slightly lower than that at exposure days in the winter, while β was significantly reduced in the summer. In addition, the energy balance ratio (EBR) was reduced significantly during flooding days in winter, while summer is just the opposite, a higher EBR was obtained. However, the ecosystem energy balance is impacted by the tide is very complex, thus more research are needed in future.