• Different maternal behaviors between primiparous sows and multiparous sows have been shown in posture changes, nursing behavior, and sow-piglet interaction. • Piglets litter weight (7 d) related to the posture change and nursing behavior. • Few behaviors, such as posture and the nursing willingness of the sow, were found to be associated with litter weight and the number of piglets crushed. This study aimed to identify the differences between maternal behaviors of primiparous sows (PS) and multiparous sows (MS), and explore the association between maternal behaviors and the litter weight as well as the number of crushed piglets. The maternal behaviors of 106 large white sows were videotaped continually for 4 h per day on postpartum day 1, 2, 3, and during week 2 (2 days/sow), and week 3 (2 days/sow). The results indicated that in the third week, PS spent a shorter time lying laterally than MS (P < 0.05). PS spent a longer time standing than MS (P < 0.05). Furthermore, a larger proportion of PS terminated nursing by sows compared with MS (P < 0.05). The frequency of nutritive nursing was influenced by the interaction between "lactation" and "parity" (PS: 37.42 ± 3.92, MS: 28.63 ± 1.91, P < 0.05). The parity and scores (carefulness score during standing to lying and the response of sows to piglets' call for help) differed in composition ratios (P < 0.05). The weight of piglets (at 7 days of age) belonging to the two groups was found to be related to the frequency of sitting to lying of sows and the percentage of nursing initiated by piglets (P < 0.05). The number of crushed piglets from PS was found to be related to the duration of lateral lying, duration of ventral lying, frequency of lateral lying to others, number of sows that terminated nursing, and piglets that terminated nursing (P < 0.05). No significant differences in the litter weight (at 7 days, 14 days, and 21 days of age) and the ratio of piglet crushing (after 7 days) were found between the two groups (P > 0.05). In conclusion, the differences in maternal behaviors between the PS and MS were evident through the time spent by sows in a posture, the nursing willingness of the sows, the composition ratio of carefulness score during standing to lying, and the composition ratio of sows' response to "piglets' call for help." However, no differences in the production performance of piglets were found between PS and MS. [ABSTRACT FROM AUTHOR]