The present study was carried out to compare the accelerative effect of shikonin (R-type), alkannin (S-type), and acetylshikonin on the proliferation of granulation tissue in rats, and to elucidate the correlation between the potency of the effect and their optical activity. Koushikon mainly contained the R-type of acetylshikonin, and Nanshikon mainly contained the S-type of acetylshikonin. Each compound produced a dose-dependent acceleration of the cotton pellet-induced granuloma formation. In comparing identical doses of shikonin, alkannin and acetylshikonin, the potency of their accelerative effects on the proliferation of granulation tissue was about the same. This result suggests that their absolute configurations (R-type or S-type) and their acetylation on the hydroxy group of the sidechain of shikonin or alkannin may not be important in producing the effect.