Abstract: During 1987 to 1989, field studies were conducted in Henan Province for the control of watermelon wilt with Agricultural Antibiotic 120 (Streptomvsis product), to compare its effect with 18 commonly used chemical fungicides. The results showed that Antibiotic 120 gave an average control effect of 83.9+11.86%, which was 23-43% higher than that of the other fungicides. It was found that the most effective method and timing of applying Antibiotic 120 were pouring its 100 ppm water solution onto the root two times before infestation of the disease. For direct sown watermelon, the first treatment was made when the plants had 4-5 leaves, and the second treatment at the same dose 7-10 days later. For transplanted watermelon, the two treatments were in seedling bed and during transplanting, respectively. This technique had been implemented in 7,333.3 ha of watermelon fields in 120 counties of Henan Province during 1987-1989. An average control effect of 70-90% was obtained.