The frequency of sandstorms has showed a decreasing trend with fluctuations in the Minqin desert area. In order to explore the reason for that, based on observations of sandstorms since 1956, and measured data of plant phenology since 1974, monthly variation of sandstorms was calculated with standard deviations while correlation between the frequency of sandstorms and climatic elements such as air humidity as well as plant phenology was computed with correlation coefficients. Results show that reduction in frequency of sandstorms is highly correlated with an increase in air humidity and has a certain relationship with advancing and postponing of plant phenology in spring and autumn respectively. The conclusions of this kind have not been reported so far at home and abroad. In particular, the relationship between the frequency of sandstorms and changes in plant phenology is a new finding, which needs to be verified by research in other regions.