Travel-related consumer generated media (CGM) plays an increasingly important role in travelers’ decision-making process. Strenuous effort has been dedicated to explore CGM’s impact on users’ travel behaviors. However, little is known about the motivations that drive users to post information on travel-related CGM. By combining the technology acceptance model (TAM), theory of planned behavior (TPB), and uses and gratifications theory (U&G), this study aims to delve into such motivational factors. The results revealed that users’ perceived ease of use when posting content significantly affects perceived usefulness. Additionally, users’ gratification derived from entertainment, information sharing, and rewards could positively influence their attitudes toward content sharing. Moreover, attitude, subjective norms, perceived behavioral control, and perceived usefulness jointly determine users’ intention to use travel-related CGM for content sharing. However, the impacts of perceived usefulness, perceived ease of use, status-seeking, socializing, and passing time on their attitudes toward content sharing were insignificant. This study tests the possibility of combining the TAM, TPB, and U&G to expand their application in the field of travel-related CGM, and provides suggestions for travel-related CGM managers to improve their services.