<p>Most previous studies on Internet altruistic behavior (IAB) have adopted a variable-centered perspective and have lacked discussions on the heterogeneity of IAB. In this study, a total of 636 college students (37.3% male) from Jiangxi Province, China, were randomly selected to explore the heterogeneity of IAB among college students of different genders using Latent Profile Analysis (LPA) and to investigate the predictive effects of social mindfulness on the potential categories of IAB among male and female students. The results show that: (1) Male and female college students have the same potential categories of IAB, including three subgroups: high altruism group, medium altruism group, and low altruism group; however, female students are predominantly distributed in the low altruism group, while male students are more likely to be in the medium altruism group; (2) The impact of social mindfulness on male and female college students’ IAB varies according to its form of expression. Specifically, tolerance and understanding, as well as optimism and open-mindedness, positively predict female students’ IAB, while kindness and respect positively predict male students’ IAB but have a negative predictive effect on female students. The findings are helpful to clarify the difference of IAB between different genders and the predictive impact of social mindfulness, and provide reference for the guidance of IAB in college students.</p>