Abstract: Tomato leaf mold is one of the most important diseases that affect the yield and quality of tomato in greenhouse cultivation. At present, chemical control methods are often used, such as Carbendazim and other chemical pesticides. Tetramycin is a new agricultural antibiotic, which belongs to biological pesticide. In this experiment, we used tetramycin to control tomato leaf mold in greenhouse. The results of field experiment showed that 0.15% tetramycin had good control effect on tomato leaf mold, and the control effect could reach more than 60% when the concentration was 600 times, so it should be used in the early stage of tomato leaf mold.