This paper describes the improvement of the prior personal computer based karyotyping system of Giemsastained chromosomes that had resolution of 256256 pixels. To upgrade the accuracy of karyotyping the resolution of the image acquisition board was increased to 512512 pixels and the algorithm of finding the centromere of a chromosome was improved. The results of the karyotyping using this improved system with an image of chromosomes taken from the Rana Amurensis had been better than the previous one.