The species Jatropha curcas of the family Euphorbiaceae, widespread in Central Africa, is a shrub 5 to 8 m high; widely used in traditional medicine. The interest of the present study is the evaluation of the hypoglycemic and antihyperglycemic activity of the aqueous extract of its roots and the formulation of capsules from the dry extract. After the harvest of Jatropha curcas in the region of the center Cameroon, roots underwent clearly a decoction in distilled water, maceration in ethanol 80 % and in pure methanol. Characterization of secondary metabolites families was performed by coloring and phytochemical precipitation tests. Subsequently, some of these metabolites were measured from standards. The animal material (male and female rats) was prepared for demonstration of hypoglycemic and antihyperglycaemic activity using as method the measurement of blood glucose every 30 minutes for 3 hours. The determination of the yields of the extracts showed a significant profitability, 8,14% for the aqueous extract. Phytochemical screening analysis and determination of phenolic compounds revealed that the aqueous extract had high levels of total phenols (24.037 mg Eq AG / g dried material), total flavonoids (9.493 mg Eq Q / g DM), flavanols (2,704 mg Eq R / g DM), flavones and flavonols (2,053 mg Eq Q / g DM), saponins (6,270%), tannins condensates (0,019 mg Eq C / g DM) and anthocyanins (2,625 mg / ml), relative to the methanolic extract and the ethanolic extract. In addition, the methanolic extract was found to be the most titrated in alkaloids (0.698%). Administration of the aqueous extract of root at a dosage of 500 mg/kg of body weight significantly decreased glycaemia (p < 0.05) compared to the group of rats which received distilled water at 10 ml/kg and showed a significant change in percentage of glucose reduction (p = 0.003), comparable to that of glibenclamide 10 mg / kg of body weight, the sulfonylurea hypoglycemic drug of reference. Our results show that the roots of J. curcas have an interesting hypoglycemic effect suggesting their use as extracts in hypoglycemic treatments.