A study on effectiveness of pyrethroid mixtures impregnated bednets was conducted both in the laboratory and the narrow fields with the initial results as follows: The Impregnated FD1, FD2 Nets (Mixture of 15-20mg Fendona + 5 - 10mg deltamethrin) on the 1m2 display had a high killing effect: The knock-down effect was 100 percent, the residual effect reached 5-6 months, the mosquito mortality ranged from 65-68 percent (for Ae.aegypti, An.dirus strains in the laboratory) and 65-70 percent (for An.minimus, An.epiroticus strains in the field). Six months after bednets treatment the non-washed nets could produce blood inhibition from 82 to 85 percent as compared with control (in tunnel tests). The Impregnated IF1, IF2 Nets (Mixture of 15-20mg Fendona + 10mg Icon) on the 1m2 display had a high killing effect: The knock-down effect was 100 percent, the residual effect after 7-8 months reached to 70-75 percent (for Ae.aegypti, An.dirus strains in the laboratory) and 65-78 percent (for An.minimus, An.epiroticus strains in the field). Six months after bednets treatment the non-washed nets could produce blood inhibition from 83 to 88 percent as compared with control (in tunnel tests). Impregnated Nets with the mixture of pyrethroid chemical group (Fendona/ICON/deltamethrin), used as alone or in combination, do not cause any side effects and safe for users.