U thong district Suphanburi province has many outstanding potentials for tourism. But there are many factors responsible for its low popularity among the tourists. The purpose of this research had analyzed the affecting the decision of group tourists visiting U Thong District. This research used quantitative research, and the research tool was questionnaires. Collected data from 400 Thai tourists. Used data selection method by Purposive sampling. Analysis of Data by factor analysis. Results indicated that there are six factors that affect the decision-making of group tourists. 1) Identity of tourist attraction (I) 2) Service of staff (S) 3) Location of tourist attractions (Lo) 4) Physical of tourist attraction (P) 5) Prices for souvenirs and accommodation (P) and 6) Public relations for tourist attractions (Pr). It can be summarized as an abbreviation: IS Lo 3P. Suggestions of this study 1) local governments should formulate cultural tourism strategies for local communities. 2) tourism management communities should improve service quality to impress tourists; and 3) continually promote marketing strategies.