Examining the Green Party Taiwan (GPT) since its establishment through the aftermath of the most recent national elections in January 2020, this book focuses on Taiwan’s most important movement party over the last two and a half decades. Despite its limited electoral impact, its leaders have played a critical role in a range of social movements, including anti-nuclear and LGBT rights campaigns. Plotting the party’s evolution in electoral politics as well as its engagement with the global green movement, this volume analyses key patterns of party change in electoral campaign appeals, organization and its human face. The second half of the volume concentrates on explaining both the party’s electoral impact and why the party has adjusted ideologically and organizationally over time. Based on a wide range of material, including focus groups, interviews and political communication data, the research relies heavily on analysis of campaign material and the voices of party activists and also considers other Green Parties, such as the splinter Trees Party and GPT-Social Democratic Alliance. Applying a wide range of theoretical frameworks to plot and explain small party development, this book will appeal to both students and scholars of Taiwan’s politics and civil society, but also to readers with an interest in small parties and particularly environmental parties and movements.