Abstract: Foliage application of fungicides in early to mid July to control secondary inoculum of Phoma. arachidicola has been the common method of contorlling peanut web blotch (PWB) in Shandong. Results of the field experiments showed that the method and timing of applying the bio-fungicide, Agricultural Antibiotic 120 (AA 120)(Streptomyces hygrospinosus var. beijingensis) were important factors influencing the control effect of the bio-fungicide against PWB. Applying AA 120 (2% water suspension diluted 200 times at 900-1,125 kg per ha.) on foliage resulted in a control effect of 21.4%, which is similar to that (29.4%) with the chemical fungicide carbendazol. Soil-surface treatment with a mixture of 2% AA 120 diluted 500 times and 40% carbendazol diluted 800 times at sowing of peanut in early May gave 48.6% control effect. The best control effect (over 70%) was obtained when two applications of the AA 120-carbendazol mature were made respectively. Soil-surface treatment in early May to control the initial inoculum of the pathogen and foliage application in -early July to control the secondary inoculum.