The present work consists of experimental analysis to study the stress-strain-strenght behaviour of saturated young residual soil in laboratory. In a first moment isotropic compression and oedometric tests where made in order to define the overconsolidation stress of the studied soil. Further, compression and extension triaxial tests where made following diferent stress paths. The axial strain have been measured through internal instrumentation (Electrolevels).A yield surface could be observed, when the sample where submitted to compression and also to extension. The secant modulus of deformability, obtained through the use of LSCDT and electrolevels used in the triaxial tests, have been analised. A microstructural study of the soil have been made from thin sections of soil, analised on the scanning electronic microscope and optical microscope, where could be possible to observe link between grains. It was caused to iron originated from weathering of biotite and garnet minerals.