This study explores the public trust in public officials` behaviors and constructs the structure of public trust in the conduct of public officials’ behaviors. Applying the general process of grounded theory, we conducted in-depth interviews with 42 interviewees, together with the qualitative research, by using Nvivo 8.0 Qualitative Analysis software to encode electronic text. Initially produced 333 open codes and six axial codes: affinitive behavior, integrity for people, hardworking and pragmatic, vocational ability, professional ethics, fair and justice. Finally, We found the process of public trust in public officials` behaviors and proposed a model: 1) Public trust is hierarchical; 2)The process of the formation of public trust is from the specific to the abstract and minute to macroscopic, which could be divided into four periods: fragile, strengthening, curing and expansion. Our contribution to extant study is that we theoretically uncover the trust mechanism of public officials’ behaviors, which would guide public officials to make normative behaviors in practice.