For a climatic field having p climatic elements in a region embedding n weather stations, the climate may be characterized by the first m major factors in the analysis with the climatic implication of each major factor discriminated by the factor loading amount. Examination of the major factors for 17 climatic elements at 100 weather stations of Shaanxi Province shows that the accumulative contribution rate of the first three major factors comes to 88.8 percent. Based on the distribution of these three major factors, the Province can be delineated into a 3-level climatic demarcation consisting of five climatic sub-zones, eleven climatic regions and twenty-six sub-regions.