The visualization of optical phase can provide abundant information when imaging transparent specimen. We present a novel phase sensitive imaging design capable of obtaining phase contours of transparent biological cells through laser oblique scanning optical microscope (LOSOM). LOSOM is based on the introduction of a fluorescent medium behind the specimen to generate a differential phase-sensitive image, thus, the complicated phase retardation alignment procedure associated with differential interference contrast (DIC) microscopy can be eliminated. Moreover, multi-modality fluorescence and phase relief imaging can be attained in a single system with fluorescently labeled specimens.