In recent years, the effective enhancement of information communication effect through governmental social media in has emerged as a universally concerned issue on government governance within the social media era. As Generation Z represents the primary and frequent users of social media, understanding the factors influencing their behaviors regarding information seeking and avoidance on governmental social media platforms is essential (in China, the principal governmental social media platform is government microblogging). Employing the grounded theory methodology, 31 participants of Chinese Generation Z were recruited for the present study, and data were collected using an in-depth interview. The results showed that the factors influencing the information-seeking behavior of Generation Z towards government microblogging mainly include heuristic seeking factors (personal preference, emotional value, and following hot topics), systematic seeking factors (task demand and expert recommendation), and defensive seeking factors (defending stance, authority seeking, and impression management). The factors influencing the information avoidance behavior of Generation Z towards government microblogging mainly include heuristic avoidance factors (clickbait titles, content layout, excessive length, and high redundancy), systematic avoidance factors (selective ignorance and terminological density), and resource-limited avoidance factors (demand scarcity, time scarcity, and vitality scarcity). This study contributes to a more comprehensive understanding of the government microblogging information behavior of Generation Z. Implications for government microblogging governance, strategy recommendations, and indicates directions for future research are discussed.