The objective of the investigation was to determine the trophic state index of the waters of the protected nature reserve "Pantanos de Villa", located in Chorrillos Lima Perú. Likewise, were evaluated the most important physicochemical characteristic parameters of the waters of the main lagoon of the area called "Genesis". For the study, it obtained 24 liters of water of the Genesis lagoon from three strategic points taken at the convenience, finding that it had an electrical conductivity at point 1 of 4315 uS/cm, for point 2 a value of 4340 uS/cm. At point 3, a value of 4320 uS/cm, all values exceeded what is established by the Environmental Quality Standard (ECA), which is 1000 uS/cm for the water of category 4 (Conservation of the aquatic ecosystem) subcategory E1 (Lakes and lagoons). As for another parameter, such as dissolved oxygen, in point 3, it resulted in the value of 6.55 mg/L, lower than ECA for water (12.22 mg/L). The total phosphorus concentration, nitrates, suspended solids, and chlorophyll concentration were also analyzed to determine the trophic state index (TSI) of the Genesis lagoon. With the data found and by calculating the Carlson TSI index, it was determined that the Genesis lagoon was in a mesotrophic state according to the Chlorophyll A parameter, according to the "transparency level" parameter, the Genesis lagoon had a eutrophic state. According to the total phosphorus parameter, it was in a hypereutrophic state.