Based on the meteorological data of 8 times per day in 4 stations over Zhejiang (Hangzhou, Zhoushan, Quzhou and Dachen) from 2000 to 2013, an analysis is made of the atmospheric mixed layer height (MLH) and their overall regional variations by the Nozaki methodThe results show that MLH in Zhoushan is the lowest, 954 m; then that in Hangzhou, 1073 m and that in Quzhou, 1181 m. MLH in Dachen is the highest, 1631 m; the spatial distribution of MLH is low in the north, high in south, and the highest in the Dachen island in Zhejiang; and the lower the MLH, the more stable it isThe variation of seasonal and daily average of MLH is obviousThe MLH changes in Hangzhou, Zhoushan and Quzhou follow the double peaktotrough pattern, which is higher in spring (from March to April) and summer (from July to August) and lower in early summer (June), autumn, and winter (November to next February) But Dachen MLH follows the single peaktotrough pattern, which is higher in autumn and winter (December to next January), and lower in late spring and early summer (May), and higher in daytime and lower in nighttimeThe increased MLH in Hangzhou of 2002 was more closely related to stronger wind speed, less sunshine and more rainy days in January and June, less rainy days in September, more sunshine in February Wind and atmospheric stability are the main factors of influencing MLHThe atmosphere is unstable when wind speed is more than 3 m〖DK〗·s-1, which is favorable for MLH uplifting This is the reason why Dachen MLH is the highest Zhoushan MLH is lower than Quzhou MLH because of lower temperature, which is why Hangzhou MLH is higher The lower the MLH, more rainy days, greater precipitation, more fog days, and the poorer visibility there are, and vice versaThe frequencies of light fog and haze appearing during same period are the highest in Hangzhou, and there will be more moderate hazes and fogs during lower MLHThe results of study are of great significance for cognitive air quality assessment and distribution of pollutant diffusion capability in Zhejiang, and it also can provide scientific reference for the rational distribution of regional pollution sources