The microheterogeneity of glycosaminoglycans was analyzed using HPSEC and PAGE. GAG preparations were analyzed five times to determine the standard deviation of the average molecular mass and the polydispersity P of each GAG with HPSEC. In addition, the Kav coefficient, the area under the absorbance time curve, and the peak purity were determined as mean and standard deviation. PAGE was performed five times using the same preparations and the average molecular mass and polydispersity were calculated. The results of PAGE and HPSEC were compared and the molecular mass distribution of the two methods was shown. The advantage of PAGE is the higher sensitivity and the resolution of oligosaccharides. The advantage of HPSEC is the better standardization, higher reproducibility, and speed.