This study was conducted to compare the aspects of behavior between miniature pigs and conventional sows during gestation and lactation periods. Miniature pigs and conventional sows at 3 parity were used in this experiment with 4 pigs per treatment. The behavioral patterns and stereotyped behaviors were observed on day 60 and 90 of gestation, at farrowing, and on day 10 of lactation before and after the feeding. On 60 and 90 days of pregnancy, both treatments showed the tendency of frequent lateral lying rather than other postures. On ventral lying, eating and drinking, miniature pigs spent more time than conventional pigs at day 90 of gestation (P<0.01, P=0.0539, P<0.05, respectively). The occurrence of stereotyped behaviors included bar biting and bar mouth chewing. At 90 day of pregnancy was observed, conventional pigs was higher than miniature pigs (P<0.05). At farrowing, miniature pigs spent more time on ventral lying, standing and walking than conventional sows (P<0.05), however, there were more frequency of drinking and eating. And on day 10 of lactation, there was no significant difference in stereotyped behaviors between miniature pigs and conventional sows. In conclusion, miniature pigs were generally more sensitive than conventional sows although sows were reared in stall during gestation and lactation period and the behavioral pattern during lactating period showed the similarity between miniature pigs and conventional sows for protection of nursing pigs. In consideration of the general reproductive performance of conventional sows, the high sensitivity and stress of miniature pigs did not affect the reproductive performance of miniature pigs.