The slices of fresh porcine tissue was investigated by exploiting our home-built photoconductive microprobe -based THz near-field imaging system . The results show that the muscle region and adipose region in the porcine tissue can be clearly discriminated in THz near-field images with a good contrast, far better than the images of the samples imaged by using the conventional terahertz time domain spectroscopy. The work demonstrated here indicates that the photoconductive microprobe-based THz near-field microscopy is feasible for the detection of biological samples and is very promising to be used in biomedical detections.