This book examines 27 types of emotions commonly seen in our society today based on a 2017 paper by Alan Cowen and Dacher Keltner in the Proceedings of the National Academy of Sciences. It begins with the nature and effects of emotions, and analyzes 14 types of positive emotions, 8 types of negative emotions, and 5 types of neutral emotions. The introduction of each emotion includes three parts: scenario stories of the emotion and explanation, emotion analysis, and emotion guidance and expression. The book mainly introduces scientific theories with literature as the complement in a logical and well-organized way, so it is both professional and fun to read.