Tumor necrosis factor receptor-associated factor (TRAF) is known to regulate antimicrobial peptides (AMPs) production in mammals. Here, to understand the immunological function of TmTRAF against microbial challenge, the induction patterns of TmTRAF against microbial infection was investigated by qRT-PCR in the whole-body and tissue of young larvae. In addition, the effects of TmTRAF RNAi on larval mortality and expression of 15 AMP genes in response to microbial infection were investigated. Our studies may help to understand the basic role of AMP production.