Some of the concepts that are encountered in various projects and programs that mention the green way of conservation and spatial solutions are green infrastructure, biodiversity, nature protection and sustainable development. In this paper, the concept of green infrastructure and the way of its application in space are studied. In the first part of the work, the problems and goals are described and the methodology of the work itself is presented. Furthermore, through a review of the available documentation, green infrastructure is described in detail within the very terms that are linked to it, but also at the European level where its importance is discussed. It is also shown at the level of the Republic of Croatia. The second part of the paper refers exclusively to the application of green infrastructure today. In this framework, inventories of the current state of the city of Zadar and the city of Knin were made, as well as historical inventories for easier understanding of the areas themselves. In this way, certain characteristics of both cities were recognized and analyzes were made that show the potential further development of green infrastructure. Certain guidelines that are already regulated by spatial plans were also taken into account. The conclusion of the entire analytical process is based on the facts that the cities of Zadar and Knin are developed in terms of built-up, that is, Zadar as a larger city is more built-up than Knin, but both cities contain a large part of undeveloped green areas that potentially represent spaces for the development of green infrastructure.