Objective To utilize partner molecular for effective expressing Musca domestica cecropin,research that partner molecular influences expression of M.domestica cecropin in E.coli.Methods Gene of mature cecropin and ubiquitin of M.domestica were amplified by RT-PCR.Using bioinformatics methods,we analyzed secondary structure of the fusion protein of thioredoxin-MC and thioredoxin –ubiquitin -MCs mRNA.