Abstract: To developing a better method of evaluating annual climatic conditions in tobacco field growing period, temperature, precipitation and sunshine times were taken as climate elements in tobacco growth process in Wannan Area. According to the tobacco growth philosophy and climate conditions, the single factor climate influence function was built, and then the comprehensive influence function was built by using with the principal component analysis (PCA) for determining the influencing weights and main factors of each tobacco developmental stage. Using 2012 data as an example, by calculating the 10-days climate influence function, drawing histogram, calculating climate anomaly and then summarizing, the analysis of climatic condition was made in the tobacco field growing period. As was the example with the histogram, it is available that made it easier to give a picture of each developmental climate effect in the growth of field tobacco. Combing with the convention climate anomaly method, the climatic influence process, content and cause in the tobacco field growing period were easier found. It also had the objective and quantitative advantages. Being with its climate average value as the basis, it can facilitate the difference of interannual and make different regional comparison available. The evaluation terms were standard and popular. It is continent for service utilization, and it also benefitted to accumulate the tobacco production management experience and promote the rational use of climatic resources in tobacco planting.