The present study was undertaken in Forest Science Faculty, Universidad de Nuevo Leon, Mexico on variability of Wood density and its possible relation to few wood chemical composition and wood fiber cell structure anatomy. The results reveal that among 10 specie studied, there exist a large variation in wood density (0.51 to 1.09), and few wood chemical composition such % carbón (37.14 to 44.07), nitrogen (9.18 to 19.22), sulphur (31.45 to 33/82), lignin (15/28 to 24.35), hemicellulose (19.94 to 27.36%), and % cellulose (33.69 to 45.92). In general, though there was no clear relationship between wood density and other chemical composition of wood. It was observed that the species having moderate to high wood density contained >40% carbón, >30% sulphur and >40% cellulose and more or less 20% lignin. It seems that carbón, sulphur, cellulose and lignin content contribute to greater density. The wood fiber cell with wall lignification seems to be related to higher wood density.