With the continuous development of public welfare, psychological investigation on the public welfare behaviors has been gradually expanded, but researches paying attention to the teenagers' Public interest-minded is rarely involved. The Public interest-minded is a relatively stable personality characteristics manifested in public behaviors. Teenagers are the potential and major participants for public welfare. Scientific research on teenagers' Public interest-minded, not only can enrich the the psychological theory of public welfare, but also give instructions and inspiration for school to cultivate juvenile moral behavior. There are both theoretical significance and practical value to probe into the characteristics of teenagers' Public interest-minded. Based on the previous studies, the present study carried out an exploratory study on the structure characteristics of the teenagers' Public interest-mind through the survey on teenagers' implicit idea on public welfare. Firstly, with 435 teenagers as subjects, we adopted Implicit Theories survey method to collect the adjectives or phrases which could describe the characteristics of the man with a Public interest-minded. Specifically, participants were instructed to write adjectives and phrases reflecting traits or characteristics of people with Public interest-minded through open questionnaire which was collected and analyzed by classification and combination, then ranked those adjectives or phrases from high to low according to frequency and lastly chose 80 adjectives and phrases representing characteristics of Public interest-minded. Selected 80 adjectives and phrases were randomly arranged to form preliminary <Questionnaire of implicit idea on public welfare for teenagers>. The questionnaire used five scoring systems with one to five from "totally agree" to "totally disagree". Secondly, we recruited 489 teenagers as participants who were required to rate the adjectives in the questionnaire according to their own understanding on Public interest-minded. Data were initially managed and processed in Excel and further analyzed in SPSS17.0. To be specific, exploratory usability testing showed that KMO coefficient was 0.916 and the value of Batley ball test was 4637.597 (df = 210, p=0.000) which provided evidence that there was a strong correlation between every single variables, demonstrating that the data were suitable for exploratory factor analysis. The principal component analysis was used for exploratory factor analysis, showing that the eigenvalues of four factors were over 1. Considering eigenvalue rules and broken stone rules, four factors could explain 59.531% of total variance. Then, the orthogonal rotation test of the variance of the four factors was conducted, and the initial results of each factor load were obtained. 59 items were deleted based on the results of exploratory factor analysis and 21 items were selected to form formal <Questionnaire of implicit idea on public welfare for teenagers>. Furthermore, four factors structure model (sympathy affection, environmental consciousness, collective consciousness, enthusiasm self-confidence) of the teenagers' public mind were confirmed through exploratory factor analysis. Finally, the adjective questionnaire scores of additional 351 teenagers were extracted for confirmatory factor analysis in AMOS19.0, and the results showed that the fitting degree of the four factors structure model of the teenagers' public mind is good, confirming the final four factor structure model of the teenagers' Public interest-minded.