Online Social Network (OSN) is an increasingly significant part in people daily life nowadays. Not only do OSNs affect lifestyle in connecting with others, sharing information and experience, creating community with old and new friends, but they also play a significant role in online commercial interaction and knowledge sharing within the organization. This paper aims to investigate the factors influencing Online Social Network continual usage in Thailand Facebook pages in the categories of products, services and organizations. Descriptive research by using self-administered questionnaire was employed. It contained information from 456 respondents who actively utilized the Thailand Facebook pages. A survey instrument was developed by applying the Expectation-Confirmation Model (ECM). The research's result found that perceived usefulness, perceived ease of use, perceived enjoyment and perceived information quality are the significant factors of users' satisfaction of OSN. Also, users' satisfaction of OSN is the significant factor of continued OSN usage intention. Specifically, usefulness was found to be the strongest factor affecting user's satisfaction. Practically, the expand ECM presents Facebook provider, Facebook Page Administrators with deeper insights into how to address Facebook page user's satisfaction and continue usage in Thailand Facebook Pages.