Abstract: The paper aims to study the change law of climate growing period in western Guanzhong under the background of global climate warming. The author used modern climate variation theory and mathematical statistics to analyze the data of daily average temperature from 11 stations in Baoji City between 1961 and 2010. The results showed that in the recent 50 years, there was a significant increase of climate growing period that had daily average temperature more than 0℃ and more than 10℃. Growing period had the most obvious rising trend during 1981-2010. Particularly, it had the longest period in 2007. Weihe River Area had the longest climate growing period, while that of Yuan Area and Qianhe Valley had the most remarkable growing trend. What’s more, there was a longer growing period in the northern mountainous area than that in the south. The growing period in western Guanzhong increased rapidly in the recent 50 years, so that both the farming season and the crop growing time extended, which were good for yield increase.