Prince of Songkla University Phuket Campus (PSU) and Hitachi Ltd. have commenced a program of joint research in the field of Thai natural language processing. As the first phase of this research, both parties have jointly developed an AI-driven prototype sentiment analysis engine capable of classifying documents written in the Thai language into positive, negative, and neutral sentiment categories. The engine analyses expressions using a sentiment dictionary refined based on approximately 100 million words of the Thai language data gathered from various social media. Although Thai has numerous specialized spoken language expressions and is known for being more difficult to process than other languages, the engine can perform high-precision sentiment analysis with support for spoken Thai expressions used on social media. PSU and Hitachi will work towards practical applications of the engine, utilizing real-time data posted on Facebook, Twitter and other social media to perform joint evaluations of the prototype, with plans to implement it as part of Hitachi's Sentiment Analysis Service(2) come April 2019.