Save energy in building environment becomes a popular concept for architects. Energy saving is not only applied to the building, but also on the urban plan and urban design, because it is proven that: urban heat island and global warming increase the near surface ambient temperature in cities. Indonesia is one of the developing countries that continue to develop. Today, sustainable development is already a major issue in development. Cities in Indonesia have at least 30% of green open space. Banjarmasin is one of the cities in Indonesian. Based on the data, Banjarmasin has the green open space of at least 5.13% in the center of the city. The increase in green open space has begun by revitalizing the area around the river into open space. Based on the measurement results: The condition of open spaces that have lots of vegetation, better thermal conditions. Open space with trees has been able to reduce environmental thermal conditions. Keywords— Green open space, thermal, SNI 03-6572