The article presents the analysis of the existing network of nature protected areas of Saint-Petersburg, which includes 8 natural reserves («zakaznik») and 7 natural monuments of regional level. Protected areas have been created from 1990 on the territory of St. Petersburg and now they cover 4.3 % of the city area. The article contains the data on the structure of landscapes and plant communities within each protected area, as well as their natural features and degree of transformation of natural complexes by anthropogenic impacts. The representation of landscapes and plant communities of the territory of St. Petersburg in protected areas is analyzed. The problems of preservation of the basic environmental functions of protected areas in connection with the processes of the natural dynamics of landscapes and the development of the city are discussed also. The perspectives of development of system of protected areas in St. Petersburg in accordance with the city laws are summarized. It is shown that interdisciplinary research involving thematic mapping, the creation of databases and GIS, gives an objective picture of the current state of protected areas and the ability to predict scenarios of their change in the conditions of the metropolis.