This article presents the study of a particular case describing the relationship between natural and anthropogenic environments which constitute the living environment of city inhabitants. The concept, based on study living environment of the inhabitants of the city of Piura in Peru, shows general characteristics of the environment, as well as the analysis of the influence that natural environment, the human factor, and law have on the living environment of city inhabitants. The author defines living environment of city inhabitants as the immediate environment where people live and which is composed of two basic elements connected with each other: the natural environment and the human factor. She formulates the hypothesis that living environment of city inhabitants represents respected value if it provides material and spiritual wellness and secures basic needs of people now and in the future. The condition of the living environment of the city of Piura is measured by quality indicator of living environment (GCAV). Final results are concluded in the presentation of two models. The first one points out the most important elements involved in the creation of the living environment of city inhabitants and stresses the necessity to maintain the balance between the natural environment and the human factor. The second model, otherwise called the model of the living environment of a Peruvian city, presents the structure and spatial relationship in living environment of city inhabitants. This model allows us to have a look at specific conditions of city environment, taking into consideration its outside environment both natural and socioeconomic.