Dengue is an infectious disease affecting 390 millions people in tropical and subtropical region annually. Dengue virus NS1 protein plays an important role in viral replication in the host cell and it is detected in high level in the infected patient serum. A synthetic gene of untagged DENV-2 NS1 with codons optimization for expression in Escherichia coli has been generated and then inserted into an expression vector pET16b. As a hydrophobic protein with aliphatic index of 71.21%, DENV-2 NS1 was produced as inclusion bodies in E. coli BL21(DE3). The DENV-2 NS1 aggregate was unfolded in 8 M urea and then refolded by reverse dilution method. The refolded DENV-2 NS1 has immunologically active structure as it is capable to interact with anti-NS1 antibody, hence making it as a potential vaccine candidate.