To control Thrips tabaci in Korean leek and green onion which grow at vinyl house in IKSAN, Jeollabuk-do, the non-treatment was set as negative control. In general treatment group, 120 mesh gauze was installed on the side window after planting(May, 2nd) and, in spring, Orius strigicollis (1.0/m2) was grazed 3 times every 7 days from mid of May which is early development stage and In the mid of June, which is the peak stage, plant extracts were sprayed one time. In autumn, O. strigicollis was grazed 3 times every 7 days from mid of September which is early development stage, and in the mid of October, which is the peak stage, plant extracts were sprayed one time. The result shows that the leaf damage ratio was decreased by 22% in Korean leek and by 27% in green onion compared to the untreatment. And the control value of Thrips tabaci shows 78.7% in korean leak and 90.6% in green onion. The density control effect of Thrips tabaci was significantly controlled under max 6.2/plant in general treatment group compared max 25/plant in the untreatment and this result was similar in green onion. The yields by general treatment was increased by 85% in Korean leek and 56% in green onion, compared with non-treatment yields, which was 900kg/10a in Korean leek and 1,287kg/10a in green onion.