In the context of the current ecological crisis, many countries, including Vietnam, are transitioning from the traditional brown economic model to an environmentally friendly green economy. However, the process of greening the economy requires significant resources, so the establishment of a green financial system is an important task of our country's economic reform program in the coming time in order to create new businesses. financial tools and products to mobilize capital for sustainable developmentTherefore, it is necessary to learn from the experiences of countries in the the world. This article will study the experience of building green financial systems in countries such as Germany, India, Singapore and Korea to draw lessons for Vietnam.