Abstract: Spring Festival factor refers to that owing to the date change of the Spring Festival each year, the observations of many economic indicators in Jan. and Feb. in one year cannot be compared with those in other years. For example, the industrial output in Jan. of the year with early Spring Festival would be less, while that in Feb. would be more. It is urgently need to be solved for analysis on short-term economic situation that how to remove the Spring Festival factor by scientific methods so that the observation in Jan. and Feb. in different years are comparable.