Gábor -Jombach: The relation between the biological activity and the land surface temperature in Abstract. The aim of our investigation was to study in detail the relationship between the spatial structure of the urban green surface and land surface temperatures. The research was carried out to support the elaboration of the Environmental Action Programme of Budapest (Hungary) focusing on city planning as well. The ultimate goal was the utilization of the findings to provide planning guidance for the city, on how vegetation could contribute to the mitigation of the negative effects of urban heat island in more effective ways.