Abstract: Based on long-term observations collected at 423 stations in China and the NCEP/NCAR reanalysis data for the period from 1961 to 2013, the influence of the East Asian winter monsoon (EAWM) and atmospheric humidity on the wintertime haze frequency over North China, Jianghuai Region and South China has been discussed. Results suggest that:(1) there is a remarkable negative correlation between the EAWM and the wintertime haze frequency. First, a weakening EAWM leads to decreases in surface wind speed, and subsequent increases in the wintertime haze frequency over all the three regions. Decreases in the number of days with daily maximum wind speed of 7-8 m/s in North China and daily maximum wind speed of 6-8 m/s in Jianghuai Region and increases in the number of days with daily maximum wind speed not greater than 2 m/s in South China have the largest impact on the wintertime haze frequency. Second, as the intensity of the EAWM weakens, the surface temperature increases, which induces increases in the wintertime haze frequency, especially in North China; (2) the relative humidity decreases in response to increases in temperature. There is a remarkable negative correlation between the relative humidity and the wintertime haze frequency in Jianghuai Region and South China; (3) the increasing wintertime temperature is conducive to the strengthening of the atmospheric stability. The wintertime haze frequency is negatively correlated with the atmospheric stability over all the three study regions, particularly with the saturation mixing ratio from 850 to 500 hPa; (4) the wintertime haze frequency in North China is significantly positively correlated with the wintertime water vapor net income. In Jianghuai Region, it is significantly positively correlated with the net income of wintertime zonal water vapor transport but significantly negatively correlated with the net income of wintertime meridional water vapor transport. In South China, it has a significantly negative correlation with the net income of wintertime meridional water vapor transport, but has no significant correlation with the net income of wintertime zonal water vapor transport.