Objective To observe the killing effects of 0.05% diphacinone sodium in the form of wax-coated poison bait corn granules, wax-coated poison bait wheat granules, or wax-coated poison bait mixed granules on Rattus norvegicus and Mus musculus in rooms. Methods A total of 760 rooms (around 15 m² every room) were selected from the area with centralized residence in Zhangma Village, Jinan, China; wax-coated poison bait mixed granules were placed in 249 rooms, wax-coated poison bait corn granules were placed in 267 rooms, and wax-coated poison bait wheat granules were placed in 244 rooms. In each room, 3 piles of wax-coated poison bait (10 g/pile) were placed for 4 d, and observation was performed for 26 d. The killing effect of wax-coated poison bait was evaluated by grid/plate method (S400). Results The killing rates of wax-coated poison bait mixed granules and wax-coated poison bait corn granules were 97.45% vs. 92.44% (u=5.22, P<0.01) for R. norvegicus and were 100% vs. 99.47% (u=1.46, P>0.05) for M. musculus. The killing rates of wax-coated poison bait mixed granules and wax-coated poison bait wheat granules were 97.45% vs. 96.59% (u=1.19, P>0.05) for R. norvegicus and were both 100% for M. musculus. Conclusion Wax-coated poison bait has good killing effects on R. norvegicus and M. musculus. Wax-coated poison bait mixed granules, which are composed of wax-coated poison bait corn granules and wax-coated poison bait wheat granules at a ratio of 7:3, have a better killing effect on R. norvegicus than wax-coated poison bait corn granules.