Objective:To evaluate the effectiveness and residual effects of trypsin modulating ecstatic factor-Bacillus thuringiensis israeliensis(TMOF-Bti) formulations against Aedes aegypti(Ae. aegypti)(L) larvae at UKM Campus Kuala Lumpur.Methods:Twenty first instar Ae.aegypti larvae were added in each bucket containing 4 L of water supplied with crushed dried-leaf powder as their source of food.Combination of TMOF-Bti in rice husk formulation with the following weights viz 10,25,50 and 100 mg,respectively in duplicate was distributed in the buckets;while TMOF-Bti in wettable powder formulation each weighing viz 2,5,10 and 20 mg,respectively in duplicate was also placed in the buckets.The control buckets run in duplicate with 4 L of water and 20 first instar Ae.aegypti larvae.All buckets were covered with mosquito netting.Larval mortality was recorded after 24 hours and weekly for five weeks.A new batch of 20 1~(st) instar larvae Ae.aegypti was introduced into each bucket weekly without additional TMOF-Bti rice husk formulation or wettable powder.The experiment was repeated for four times.Results:The result of the study showed that all formulations were very effective on the first two weeks by giving 100% larval mortality for all concentrations applied.The TMOF(2%) + Bti(2%) had a good residual effect until the end of 3~(rd) week,TMOF(4%) + Bti(4%) until 4~(th) week,wettable powder TMOF(20%) + Bti(20%) until the third week.Condusions:From the results it can be concluded that the TMOF-Bti formulations can be utilized in dengue vector control. Objective: To evaluate the effectiveness and residual effects of trypsin modulating ecstatic factor-Bacillus thuringiensis israeliensis (TMOF-Bti) formulations against Aedes aegypti (Ae. Aegypti) (L) larvae at UKM Campus Kuala Lumpur. Methods: Twenty first instar Ae. Aegypti larvae were added in each bucket containing 4 L of water supplied with crushed dried-leaf powder as their source of food. Combine of TMOF-Bti in rice husk formulation with the following weights viz 10, 25, 50 and 100 mg, respectively in duplicate was distributed in the buckets; while TMOF-Bti in wettable powder formulations each weighing viz 2,5,10 and 20 mg, respectively in duplicate was also placed in the buckets. The control buckets run in duplicate with 4 L of water and 20 first instar Ae.aegypti larvae.All buckets were covered with mosquito netting. Larval mortality was recorded after 24 hours and weekly for five weeks. A new batch of 20 1 ~ (st) instar larvae Ae. aegypti was introduced into each bucket weekly without additio nal TMOF-Bti rice husk formulation or wettable powder. The experiment was repeated for four times. Results: The result of the study showed that all cells were very effective on the first two weeks by giving 100% larval mortality for all concentrations applied. TMOF (2%) + Bti (2%) had a good residual effect until the end of 3 ~ (rd) week, TMOF (4%) + Bti 20%) + Bti (20%) until the third week .ondusions: From the results it can be concluded that the TMOF-Bti formulations can be utilized in dengue vector control.