In this paper, the authors analyzed basalt samples from Southwest Indian Ridge. These samples are fragments of basaltic pillow lavas and sheet flows. These samples are mainly porphyritic with fine-grained, and euhedral to anhedral phenocrysts of plagioclase, olivine and pyroxene. The data indicate that mantle melting in the study area occur in higher degree and at deeper depth. Furthermore, petrologic and mineralogical features of basalts at 49.6°E and 50.5°E suggest that magma activity and source in the study area are complex.