Colocynth ( gourd) "Citrullus colocynthis, plants of cucurbitaceae family, native to arid soles, used as treatment of many diseases in traditional medicine in Mediterranean countries, rich in polyunsaturated fatty acid. This study aimed to compare the effect of diets rich in fat (MG) supplemented with colocynth oil (HC) and sunflower oil (HT) on weight changes and digestibility of nitrogen Wistar rats. In this work the male Wistar rats weaned to a weight of 80 ± 5 ,were divided into four groups and receive different food diets (R) for 2 months (R1: 16 Ã?¢Ã?â??Ã?â?¦ Ã?¢Ã?â??Ã?â?¦ casein + 8 HT, R2: 16 Ã?¢Ã?â??Ã?â?¦ casein + 8 Ã?¢Ã?â??Ã?â?¦ HC, R3: 16 Ã?¢Ã?â??Ã?â?¦ casein + 30 Ã?¢Ã?â??Ã?â?¦ MG + 8 Ã?¢Ã?â??Ã?â?¦ HT, R4: 16 Ã?¢Ã?â??Ã?â?¦ casein + + 30 Ã?¢Ã?â??Ã?â?¦ MG + 8 Ã?¢Ã?â??Ã?â?¦ HC) The weight of the rats and the amount of food ingested are taken daily, balances nutrition and nitrogen were made during the first, fourth, fifth and eighth week of the experiment. The extraction of oil from seeds of the gourd was made by the soxhlet apparatus and nitrogen determination was made by the Kjeldahl method. L (1883). The results show a slowing of weight change with increasing food intake, and decreased protein digestibility in rats fed with diets containing oil of gourd compared with rats (control) consumes diets of sunflower oil. The oil of gourd obstacle excess body fat in the body and it may be due to the influence of oil on the digestibility of proteins