To investigate whether RNA interference suppressor P19 derived from tombusvirus can enhance baculovirus yield and transgene expression. A number of recombinant baculoviruses with P19 under the control of white spot syndrome virus immediate-early promoter, baculovirus early-to-late promoter, or P10 late promoter were constructed The budded virus titer and the expression levels of eGFP and luciferase were determined. P19 was clearly functional in Sf9 cells and could enhance baculovirus yield, eGFP and luciferase expression levels up to 6.8-, 1.8-, and 2.1-fold respectively, at 72 h post infection. P19 enhanced baculovirus production and transgene expression, and thus has potential applications in baculovirus-based gene therapy and vaccine studies.