AbstrAct – A study was conducted to evaluate the effect of feeding management and seasonal variation (summer and winter 2007) on fatty acid composition of Mexican soft raw goats' milk cheese. Four groups were formed. During the summer, group A grazed on a natural semiarid rangeland. group B was kept in confinement, fed with concentrate grains and lucerne hay. Through the winter group C grazed on the same rangeland with supplementation and group D was fed as the group B. Thereafter, four kinds of cheeses were manufactured from milk of each animal group: grazed-summer (GS), in-door-summer (IS), grazed-winter (GW) and indoor-winter (IW). Results of this study indicated that fat content in cheese was affected by season. Moreover, during the summer period, pasture-based regime increased monounsaturated and polyunsaturated fatty acid concentrations; however, winter season could diminish the cheese desirable fatty acid profile. Introduction – Although traditionally in Mexico goat milk has been processed as a candy, lately a steady growing amount of goat milk has been used for cheese production (Galina et al., 2007). Regar-dless of the fact that many questions remain unclear concerning about the optimal goat production system, plant biodiversity of semiarid resources have been conventionally use as a part of goat diets (Cuchillo et al., 2009; Puga et al., 2009). However, it is not well known whether this pastoral system could affect cheese composition in different seasons (Morand-Fehr et al., 2007). Therefore, the present study compares the effect of two feeding systems (grazing and an indoor full feeding system), on the fatty acid composition of artisan goat milk cheese in summer and winter. Material and methods -The study was conducted in Querétaro, Mexico, during 2007. Four groups (A, B, C and D) were formed, each with 20 French Alpine goats. During the summer, group A after milking grazed 8hours/d on 14ha on a semiarid rangeland, with overnight confinement. group B was kept indoor, fed daily with 1kg of concentrate grains (18% of CP and 2.5 Mcal/kg) and 1.5kg of lucerne hay. Through the winter group C after milking grazed 8 hours/d on the same rangeland as group A, supplemented with 200g of concentrate grains in the morning and 300g of lucerne hay in the evening. group D was managed as the group B. Five times in each season, 40kg of daily milk raw were col-lected from each group. Therefore four kinds of cheeses were manufactured: grazed-summer (GS), indoor-summer (IS), grazed-winter (GW) and indoor-winter (IW), obtaining five batches for each kind of cheese, with a total of 20 samples. Moisture (oven-drying at 60°C) and ash (burning at 550°C in an electric furnace) were determined using standard methods (AOAC, 2003). Nitrogen was measured using the Kjeldahl method (AOAC, 2003). Gross energy was determined using the calorimetric Parr bomb (Parr Instrument Company, Illinois. USA). Total lipids were determined according to Folch et al. (1957). Methyl-esters were carried out according to official method 696.33 (AOAC, 2003), using gas