A study on the feeding of camel herds was carried in the pastoral area of Agadez in Niger. The aim of the study was to describe the botanical composition of daily feed of camels on rangeland during three seasons (hot dry season, cold dry season and rainy season) and to assess the chemical composition and nutritional values of plants consumed by camels to see what is their input of energy and crude protein to the animals. Six herds of camels have been regularly monitored from September 2002 to August 2003. The “collect of shepherd” (Guerin, 1987) was the method used to study the botanical composition of diet. Previously, rangeland were studied in order to know their floristic composition using the method of “quadrat- point” of Daget and Poisson (1971). Twenty herbaceous species have been described in three sites with a predominance of graminae (grass) (58.67%). The diet of camel contain, whatever the season, herbaceous (grasses and others) and ligneous plants. These last represent 5%, 44% and 89.5% of the components of the diet during respectively the rainy season, the dry cold and hot seasons. No crop residue is associated in this diet. Chemical analysis showed that the plants consumed have a high rate of mineral matter. Three plants contained high rate of energy value (UFL), as Boscia senegalensis (0.81 UFL / kg DM), Acacia nilotica (0.91 UFL / kg DM) and Acacia erhembergiana (0.88 UFL / kg DM) . Concerning the digestible crude protein input (DCP) Salvadora persica (159 g MAD / kg MS), Maerua crassifolia (148 gMAD/kg MS) and Boscia senegalensis (213 gMAD/kg MS) were distinguished themselves. So the ligneous plants are the main providers of nutrients (protein and energy) in the diet of camels in this area particularly during dry hot season and dry cold season because they represent respectively 89.5% and 44% of plants consumed each day by camels.