The aim of current study is to explore the construct of homeroom teachers’ self-efficacy in guidance. The study adopted stratified clustering sampling process and included 296 homeroom teachers from Taoyuan City. A questionnaire was developed to study the homeroom teachers’ self-efficacy in guidance. In pre-test, item analysis and exploratory factor analysis (EFA) were performed to investigate the item quality and factors construct. Then, CFA was further conducted to confirm the factor constructs of homeroom teachers’ self-efficacy in guidance. The results of CFA produced five constructs that consisted of teacher-student relationship, class management and positive disciplinary, problem solving and conflict resolving, identifying signs of adjustment problems, and system cooperation. The factor loadings of 42 items ranged from .64 to .85, the correlations between five factors were from .87 to .97, and the Cronbach α’s were from .87 to .92 for five factors. The CFA model fit index were χ2/df=2.361, other fit indexes included CFI=.900, IFI=.901, SRMR=.042, RMSEA=.068. In addition, self-efficacy in guidance showed significant differences with regard to different gender, age, marriage status, years of service, grade of teaching, and background education in counseling (P<.05).