Titas Gas Transmission and Distribution Company Limited is the largest gas distribution company in Bangladesh. A total numbers of employees 2100 have been working in this sector. To measure factors hold key to job satisfaction of the human resources of the company, a sample of 115 employees were selected from head office, Dhaka, Gazipur, Mymensingh, Narayanganj offices on a random purposive sampling basis and data were collected through closed end questionnaire from field study on offices. To ascertain job satisfaction, 13 factors like job security, salary, promotion, job status, working condition, supervision, award, relation, communication, duration, participation and training were chosen. Different types of statistical tools like descriptive statistics, regression analysis, factor analysis, Mann-Whitney U- Test and Kruskal Wallis Test were used for analyzing and interpreting data. The study revealed that low level salary holders were more dissatisfied. It is shown that higher level of pay holders was highly satisfied on autonomy, participation, location, training etc. The study further indicated that the employees of Dhaka and Narayanganj revealed in foremost facilities than that of other located areas. The study also identified three factors are Factor-1: Developed monetary based human resources facilities; Factor-2: Technologically advanced facilities based on working conditions; Factor-3: Satisfactory level of practicing autonomy to be the most influential that in fact reflect as key factors of job satisfaction of human resources of TGTDCL in Bangladesh. Management of the company should provide adequate facilities and allocated to the employees maintaining equity to ensure legal rights disregarding manipulations of outwards intervention that damages the congenial environment of the organizational environments and lead to dissatisfactions of the human resources.