One of the main problems with polymeric materials is their variability with respect to time, because of the difficulty predicting the behavior when it´s subjected to different environmental media such as temperature, humidity, pressure and weather conditions. The polypropylene (PP) thermal oxidation had been frequently analyzed, Fayolle et al (2008), Mueller et al (2003), Richaud et al (2008) and Vink et al (2000), but photo oxidative is less known (Gallo et al. 1997, 2006, 2013). The material used in this investigation is a geotextile, TR 4000 m®, manufactured from PP woven in raffia. Its mechanical properties have been measured before and after an accelerated photodegradation in order to evaluate the behavior of the material with respect to time. The material was exposed to UV-A radiation, measuring its properties at 0, 75, 150, 300 and 500 hours. The mechanical properties measured in this study were: Index Puncture Resistance of Geotextiles (ASTM D4844), Trapezoidal Tearing Strength of Geotextiles (ASTM D 4533) and Tensile Properties of Geotextiles using the wide strip method (ASTM D4595) in both directions, longitudinal and transverse. Simultaneously, a carbonyl index FTIR test was performed measuring the absorptivity change at a wavenumber of 1710 cm-1, in order to establish a relationship between the variation of the change in mechanical properties and the level of oxidation of the materials subjected to accelerated aging. As can be seen from results, all mechanical properties vary with the time, specially tear resistance that correlate linearly with the carbonyl index change. It´s required to extend the observation period and validate this type of response with other polymers as PET for example to propose the Trapezoidal Tearing Strength as a new direct degradation measurement of geotextiles. Keywords: Polypropylene, photodegradation, accelerated ageing, carbonyl index.