This study was conducted to develope efficient vermicomposting using of different mixture ratios of cow manure and sawdust by feeding these to earthworm and then by studying the growth and reproductive efficiency of earthworm, and the chemical composition of worm cast and its production. The results are summarized as follows. C/N ratio of feed was 20.43~45.20 and it increased according to the higher proportion of sawdust, and survival of earthworm was 97.6~100%. Number of young worms were significantly higher in 30 and 40% addition of sawdust (number of 899.6 and 927.8) than number of 769 of real cow manure treatment (P<0.05). Fresh weight of young worms was 8.00~14.35g and it was significantly higher in 40% addition of sawdust than other treatments(P<0.05). The cast production of earthworm was showed in the tendency of becoming lower in the 40% addition of sawdust than in 10~30% addition of that, but digested matters were significantly higher in 10~40% addition of sawdust than real cow manure treatment(P<0.05).