Based on the eddy covariance (EC) system, the mean diurnal changes of carbon flux (Fc) and vapor water flux (Fw), especially during the growing season of Phyllostachys edulis stand were analyzed in Shanchuan site of Anji County, Zhejiang Province during June to September, 2011.Accordance with the variation characteristics of environmental factors of rainfall, vapor pressure deficit (VPD) and net radiation data, the relationships of water use efficiency (WUE) and environmental factors also were studied.The results showed that there existed consistency variation between carbon flux and vapor water flux during the day time.It was a U shape with single peak.On the daily scale, both carbon flux and vapor water flux increased gradually and reached the peak value at 11:00 and 13:00, respectively.At noon, both of them had little decline, then they decreased gradually in the afternoon.On a daily scale, water use efficiency was the lowest in the morning, reached the highest in noon, and then decreased in afternoon.The trends of carbon-water fluxes were multiple small peaks in the daily change.On a monthly scale, they was no more strange variation in June, July and August, however, it was varied much more complicate and fluctuating in September.The maximum value of WUE was 8.58 mg CO_2·g~(-1) H_2O in September, and the minimum was 5.12 mg CO_2·g~(-1) H_2O in August.There was a significantly positive correlation of WUE and VPD at daily scales during the growing season.Besides, the water vapor flux was significantly negative correlation with carbon flux (Fc) during the main growing season of Moso bamboo.And nonlinear logarithmic fitting (R~2=0.6947) of them was much more significant than linear fitting (R~2=0.5947), which indicating that the coupling relationship of carbon-water could be changed as a result of seasonal changes of climate condition.We suppose that the reason is the inconsistent distribution of hydrothermal resource, and it is not useful to the efficient use of water resources in this ecosystem.