This study was conducted to investigate the numerical measurements of chestnut weevil, Curculio sikkimensis, reared in the lab and outdoor field from 2003 to 2006. Numerical measurements were calculated for the sex ratios, fresh weight, body length and width, head width, proboscis length, and antennal length. The female adult was bigger than male in fresh weight, body length and width, head width, proboscis, and antennal length. The size of egg was showed 0.8±0.03mm (n=20). Larval instars was measured 98 mg in body weight, 10.65 and 3.99 mm in body length and width, 1.70 mm in head width. Pupal size was also measured as 7.01±0.65mm in female, 6.53±0.48mm in male. The larva of C. sikkimensis overwintered through 3 years and the size of body weight, body length, and body width were decreased.