Chapter 1 introduces the research background, significance, content, methodology and contribution. We focus on green trade barriers (abbreviated as GTBs) and their impact on environmental and economic outcomes, particularly for Chinese export-oriented firms. It outlines the historical context of the relationship between trade and environmental protection, noting the evolution of global environmental policies and the rise of GTBs in the 1980s. These barriers are aimed at promoting sustainable development but can also impact international trade by imposing environmental regulations. The study investigates how the GTBs affect pollution emissions and green innovation in Chinese firms, exploring the mechanisms through which these measures influence industrial transformation. It examines the complex impact of GTBs especially the long-term benefits such as pollution reduction and green innovation. The research employs micro-level data from Chinese enterprises to analyze firm-level responses and aims to fill gaps in existing literature by focusing on heterogeneity across firms and regions. The study's theoretical and practical significance lies in understanding how GTBs shape the green transformation of industries and provide strategic insights for developing countries navigating global trade and environmental challenges.