Due mainly to the importance of organizational commitment for both employees and employers, it has been the subject attracting researchers over the last few decades. Therefore, the paper aims to build a model of antecedents strengthening organizational commitment. First, the paper reviews six main concepts including organizational commitment, intrinsic motivation, extrinsic motivation, employee voice, organizational identification and perceived organizational support. Next, Five-point Likert scale is used to measure those factors with two hundred and forty-nine fulltime Vietnamese employees who are working at 34 Vietnamese organizations from a variety of sectors such as tax, banking, health service, airlines, education and business. Finally, quantitative research is obtained by using EFA, CFA analysis and structural equation modeling. The findings show that three prominent factors positively affecting organizational commitment are intrinsic motivation, extrinsic motivation and organizational identification.