This paper introduces a dynamic model to illustrate how the self, the work, and the environment interactively influence the experience of work meaningfulness during the employment period. While individuals might enter an organization with intent to improve or protect others¡¦ well-being, their perceived degree of work meaningfulness might be strengthened or weakened within jobs. Other factors from their work and the environment could come into play. Specifically, the proposed model presents how the interplay between prosocial motivation, perceived task significance, and perceived external prestige of an organization affect the experienced meaningfulness of work jointly. This paper tests the model by surveying employees from the high-tech sector and the police sector using the questionnaire method. The results show that individuals who have prosocial motivation indeed experience a sense of work meaningfulness initially. Even when individuals are prosocially motivated, the perceived external prestige of their organizations positively affects their experience in meaningfulness of work. Furthermore, the perceived level of task significance of one¡¦s work overpowers the existing prosocial motivation when it comes to altering the perception of work meaningfulness. The findings indicate that factors from different dimensions could alter the experienced meaningfulness of work together, and the relation between prosocial motivation and work meaningfulness is dynamic.