This study was conducted to clarify behavior and body weight of weaned piglets between different social experiences during suckling period. Control (no social experience) and treatment (social experience) groups of weaned piglets were housed and observed with the aid of video technology for 8 consecutive hours in early (days 1 and 2) and late (days 22 and 23) periods after mixing. Inactive, locomotion and exploration were significantly different between control and treatment groups in early mixed period. Feeding differed between groups in late mixed period. In social behaviors, agonistic and interaction with adjacent pen were significantly higher in treatment group than in control group during early mixed period. However, social behaviors dramatically decreased in late mixed period. There was negative correlation between average daily gain of body weight and agonistic behavior. In social experienced weaned piglet groups, there were less agonistic behavior and more daily gain of body weight in this study. Social experience during suckling period would be useful for stable group management in swine industry.