Abstract: Cryptos have emerged and played an important role in financial market. The researcher draws from the theory of the relationship between social media and crypto equity value. This research hypothesizes that social media affect crypto valuation. The research attempts to construct an appropriate Thai sentiment dictionary for cryptos to improve a textual sentiment analysis, and to understand the relationship between social media sentiment variables and crypto valuation. The designed system architecture composes of six modules: data acquisition, data preprocessing, sentiment dictionary construction, sentiment estimation, sentiment categorization, and time series analysis. The outcomes of the research would be an appropriate Thai crypto sentiment dictionary, a method useful to estimate sentiment of posts on social media, and the understanding of the predictive relationship between crypto valuation and social media.