This study was carried out to investigate the effects of the wound contraction of chitosan, aloe vera, fucidin natrium, and premycin ointment on defected wound from full-thickness skin defects(1 cm x 1 cm). Twelve dogs were designed in 5 different positions on the dorsal thoracolumbar. We examined the effects of wound contraction every four other day 16 for days. Percentage of wound contraction based on epitherial overall area of defected wound which calculated by image analyzer and computer. Four to 8 days after wound contraction in wound defected dogs, the epithelial overall rate were the most high presented by 48.1% in the chitosan group and were the lowest by 26.8% in the premycin group. In 16 days, chitosan group were the most heigh presented by 94.4% and premycin group were the lowest by 76.5% compare to saline group of 85.9%. Thus, we conclude that the chitosan is a possible role for improvement of wound contraction by wound defected dogs.