Heterogeneous catalysis has been recognized as one of the most promising alternatives for the solution to many of the environmental and operational problems presented by the conventional production of biodiesel. The purpose of this research was to study the catalytic activity of various catalysts solid basic nature from MgO, modified by hydrothermal treatments and wet or dry impregnation of alkali metals in the transesterification of triacetin (molecule model) with ethanol. We analyzed the influence of: hydrothermal treatment, type and amount of alkali metal impregnated (Li, Cs, Rb) and the activation on the basicity and catalytic behavior of the catalysts. The reactions were conducted in a batch system with a molar ethanol: 10:1 triacetin and 3% by weight of catalyst. The reaction was followed by gas chromatography. The activation of MgO modified with Li, Rb Cs or caused an increase in the number of sites on its core strength, increasing the catalytic activity. These three catalysts have the same selectivity to ethyl ester (80%), the diglycerides (12%) and monoglyceride (8%).