Abstract: The pot experiment and field experiment were carried out to study the control effects of Phytophthora blight and plant growth promoting effect of sweet pepper by Trichoderma harzianum. The results showed that，in pot experiments，the control effect reached 71.3%，plant height，thick stems，chlorophyll content were 1.71 cm，0.514 mm，6.317 higher than those of positive control after 20 days，respectively. And leaf number and leaf area were increased by 0.86 and 0.59 cm2 than those of positive control，respectively. In field experiments，the control effect reached 74.6%，chlorophyll content，plant height，thick stems and production were 3.92，5.79 cm，0.85 mm and 35.39% higher than those of positive control， respectively.

Key words: Trichoderma harzianum, sweet pepper, Phytophthora blight, growth promoting effect, control effect