This paper studies the influences of forest regeneration on the species diversity of sarcosaprophagous beetles (Coleoptera) in Wolong Natural Reserve (102°52′-103°24′E, 30°45′-31°25′N), Southwestern China. Comparisons were made among larch plantations dominated by Larix kaempferi of different ages (namely, 5 years, 15 years, and 45 years after being planted) and natural deciduous broad-leaved forest (ca. 100 years old). Baittraps were used in the field collections and laid in two ways, on the ground and 1.5 m high above the ground. A total of 3 066 beetles were collected, of which 43.71% belonged to Staphylinidae, 31.83% Leiodidae, and 17.97% Silphidae. These three families are so considered as dominant groups. Species-abundance patterns fit the lognormal distribution; the patterns of the larch plantations, as their age increases, resembled more and more closely to that of the natural broad-leaved forest. Species richness and diversity were significantly lower in the larch plantations than in the natural broad-leaved forest, and the lowest values of both were observed in the 5-year-old larch plantation. Based on the species composition and abundance, sarcosaprophagous beetles of the three larch plantations and the adjacent natural broad-leaved forest could be separated from each other by ordinations based on principal coordinate analysis (PCoA) and cluster analysis. Our results showed that larch plantations could not completely replace natural broad-leaved forests in the role of conserving the biodiversity of sarcosaprophagous beetles.