Abstract: Practical techniques of treating waste pulping liquid from small scale straw pulp mills, which have been conducted as the national major scientific and technical plans during the Seventh-Five-Year-Plan (1986-1990) have been briefly introduced. These practical techniques include; (1) simple recovering of alkali; (2) acidification of alkaline pulping waste liquid to get lighin and utilize it cmprehensively; (3) anaerobic digestion of lime straw pulp waste liquid; (4) recovery of alkali by electrodialysis process and (5) anaeribic digetion of the alkaline pulping waste liquid after lignin separated by acidification. It is suggested that the research on these practical techniques in produ’ctio scale should be continued and that two or three complete sets of practical technique of preventing and treating contamination for thousands of small-scale straw pulp mills should be developed.