The influence of service and promotion of marketing mix toward the decision of participants in joining vocational training at Balai Latihan Kerja Lembang. The research aimed to find out the influence of servicet and promotion of Marketing Mix toward the decision of participants in joining vocational training at BLK Lembang. Research method used in this research was associative and qualitative method. The research provided primary data. The data collection technique used in this research ware library research and field research such as observation and questionnaire. Methods of data analysis used by the researcher were classic assumption test that includes validity test and reliability as well as hypothesis test consisting of partial test and simultaneous test. The research found that servicet and promotion of marketing mix give great influence toward decision of participants in joining vocational training. According analysis process recognized that there was strong and positive correlation marked by score r=0.897 and R2= 0,805. It showed that servicet and promotion of marketing mix influenced the decision of participants in joining vocational training in the amount of 80,5%. Besides, the remaining result of 19,5% was influenced by the certain factor that was not analysed in this research.The research was expected to give advantages toward BLK Lembang in improving its service servicet in order to maintain the quality of training service servicet in BLK Lembang that has been well accepted by training participants. In improving its service training servicet, BLK Lembang should enhance its service training based on public’s demand and increase promotional effort to let the participant know that BLK Lembang provides free training program.