Sex differences always occur in parental investment and behavior during the breeding season in socially monogamous birds. Here, we described a study that used real-time video monitoring to examine the characteristics of parental investments and strategies in Sittiparus varius from March to July, 2017. The results were as follows: (1) there was no significant difference between the feeding rate of the male and female parent in the early period, while the feeding rate of the female was more than that of the male in the later period, (2) with increasing age of the nestlings, females increased their feeding frequency, while the males did not, and (3) the feeding rate of the female parent was positively correlated with its beak size, while no correlation was found between feeding rate and the male's physical characteristics. Overall, in Sittiparus varius, the feeding rate of the female is adjusted according to the demand of the nestlings and related to individual characteristics, while the male shows no change during the breeding season. This difference may be associated with the divisions of labor during the feeding period.