Buckwheat is mainly distributed in central and western regions in China, is one of the major food crops and economic crops in these areas. The production and development of buckwheat have direct impact on farmers' income and agricultural economic development of these areas. The climate regionalization of buckwheat quality is the important basis of optimizing cultivation environment and quality variety layout, and has a great guiding meaning towards high quality production of buckwheat. So, exploring the best planting pattern of buckwheat can provide theoretical and practical basis for the regionalization and high quality buckwheat production at larger scales. But the current climate regionalization studies of buckwheat mainly focused on the suitable cultivation division using traditional research methods, and no report about climatic regionalization of buckwheat quality using principal components analysis (PCA) and GIS was found. In this study, the correlation of quality index of buckwheat and meteorological factors was analyzed, together with the geographical distribution information of buckwheat and the major meteorological factors which effected on quality index were screened out. The model was established based on PCA method in order go assess the comprehensive quality of buckwheat, then the ecological regionalization was determined using the ArcGIS spatial analysis technique. The results showed that temperature, rainfall and sunshine-hour were the main ecological factors which effected buckwheat quality index. It had bad effect on buckwheat growth and went against accumulate of quality index, if the daily highest temperature was more than 35℃ and mean temperature was higher. A plenty of precipitation in August and plenteous sunshine of whole stage were beneficial to accumulate of quality index. Combined with evaluation model, using GIS, Jinzhong Prefecture was divided into three regions, i.e. adapted, inferior adapted and bad adapted planting region, and it was largely in line with the actual condition. PCA combined with GIS method is the most powerful approach for regionalization, and the quantitative computing and qualitative analysis are integrated. So, there is a feasibility to carry through ecological regionalization of buckwheat quality using PCA method and GIS, and the regionalization results are objective and scientific. The method is concise, applicable and effective, which can really reflect the regionalization actual situation and provide reference for fine quality production of buckwheat.