Online Social Network (OSN) such as Facebook and Twitter is an increasingly significant part in people daily life over the globe. While a lot of people are spending an increasing amount of time using OSN sites, others use them minimally or discontinue using them after a short period of time. This paper aims to investigate the factors influencing Online Social Network continual usage inThailand Facebook pages in the categories of products, services and organizations since there is little research exploring the continuous usage of OSNs, especially in Thailand. A survey instrument was developed by applying the expectation-confirmation model (ECM). The research result found that perceived usefulness, perceived ease of use, perceived enjoyment, perceived information quality are significant factors of users’ satisfaction of OSN. Users’ satisfaction of OSN is significant factor of continued OSN usage intention. Specifically, usefulness was found to be the strongest factor affecting user’s satisfaction.