A program system for microcomputer assisted karyotype analysis of banded chromosomes is presented. Measurement is done with a digitizer pad (graphics tablett), the quantification and statistical calculation is processed by a computer program with a microcomputer DEC PDP11/23. The significant karyotype parameters can be calculated and plotted in an idiogram: length of the chromosome arms, centromeric index, position of secondary constriction, position and size of bands. The program system is exemplified in C-bandedHyacinthoides italicas.l. (Hyacinthaceae), which shows a rather complex banding pattern.