The relationship between plant diversity, productivity and environmental factors in the dryland is an important subject of ecological research, which will provide scientific guidance for revealing the environmental adaptation mechanism of vegetation in this area. Based on systematic sampling and in-situ investigation along the east-west transect in the dryland of northern China, the effects of various factors on diversity and productivity, and the regulation mechanism of productivity were quantified. The results showed that:(1) the relationship between community weighted mean trait values and aboveground biomass in the dryland (R²=0.46) was stronger than that between Shannon-Wiener index and aboveground biomass (R²=0.21). (2) The Shannon-Wiener index, community weighted mean trait values, and aboveground biomass in the dryland were positively and linearly correlated with mean annual precipitation, soil organic carbon content and total soil nitrogen content, while were not significantly correlated with total soil phosphorus. The Shannon-Wiener index and community weighted mean trait values were negatively and linearly correlated with mean annual temperature, while the aboveground biomass was not significantly correlated with mean annual temperature. (3) The mean annual precipitation explained 40.9% of the change of community weighted mean trait values in the dryland, and the two were positively correlated. The mean annual temperature explained 28.3% of the change of Shannon-Wiener index in the dryland, and the two were negatively correlated. (4) The direct path of community weighted mean trait values to the aboveground biomass was significant. The mean annual precipitation, mean annual temperature and soil organic carbon indirectly affected aboveground biomass through the community weighted mean trait values.