This study investigates the key success factors of Taipei City Worker Union, which has introduced the TTQS (Taiwan TrainQuali System) to control the validity of training. The process of this study could be separated into 3 parts: questionnaire design, interview, survey and analyze. First, going trough documents to collect and combine difference thesis to build a solid questionnaire. Afterward, interviewing with people who are in charge of TTQS project in Taipei City Worker Union and TTQS of auditor. Finally, analyzing the information and the result of survey based on grounded theory of qualitative research. By using the grounded theory we could learn that the achievement of this case is attributed to 4 main aspects (organization management, training planning, training project executing and training evaluating) and 16 key factors. In short, after analyzing 4 main aspects and 16 key factors of the relative weight by Analytical Hierarchy Process (AHP). The study results above-mentioned substantial operations to those whom Taipei City Worker union, TTQS Scorecard for Trainer. Final, this study provides concrete suggestions follow-up researchers may concern with TTQS projects in future.