Abstract: Abstract: The paper aims to reveal temporal and spatial evolution of gale days and it effect on sand-dust weather and defend and mitigate the wind and sand disasters better. Based on gale, sandstorm and flying sand observational data from 4 meteorological stations in east of Hexi corridor from 1971 to 2010, the temporal and spatial evolution of gale days and the relationships between gale days and sandstorm, flying sand days were analyzed. The results show that the annual gale days decrease significantly with the rate of 10.77d/ decade in east of Hexi corridor in recent 40 years, so are the seasonal gale days and the decreasing rate is the largest in summer and is the smallest in winter. The gale days of year and season show decreasing trend with increased of age. The gale days is the most in spring and is the least in autumn, and the maximum occurs in April and the minimum appears in September. The spatial distributions of gale days are related to altitude and topography, the gale days is the most in high altitude mountain and is more in northern desert area and shallow mountain area and is the least in oasis plain. The annual sandstorm and flying sand days decrease significantly in east of Hexi corridor in recent 40 years. The annual sandstorm and flying sand days are significant positive correlations with annual gale days, and the correlation coefficients are 0.878 and 0.888 respectively. The variation of gale days has a remarkable positive effect to the variation of sand-dust days with time, and the decrease of gale days may be one of main reasons for the decrease of sand-dust days.