AeSCP-2, a sterol carrier protein, is involved in sterol trafficking in mosquitoes. The activity of the AeSCP-2 gene is important for mosquito development. An earlier study demonstrated that the transcription of this gene was up-regulated by 20-hydroxyecdyson in cultured tissues. We isolated 0.2 kb, 1.6 kb and 4.2 kb upstream promoter sequences and linked them to a reporter gene. Aag-2 cell line was transfected with these promoter/reporter constructs and treated with ecdysone at various concentrations. Over-expression of different combinations of mosquito transcription factors (USPA, USPB, EcRA, EcRB and Ftz-F1) were also co-transfected with the promoter/reporter constructs. The observed results demonstrated that different combinations of transcription factors produce different promoter activities of the AeSCP-2 gene. This observation leads us to the conclusion that the partnership of transcription factors is crucial in regulating transcriptional activity of AeSCP-2 gene.