Résumé : The object of this paper is to study the distribution of chromosomes in the metaphase figures of human leucocytes cultures. We studied, in the group A, the chromosomes 1 and 3, easily recognisable; in the group B: the chromosomes 4 and 5 and in the group G: the chromosomes 21, 22 and the sex chromosome Y. The method we used consits in calculating the real distance of the centomer of a chromosome to the center of the figure. We compared one distribution to the other and we submitted our results to some statistical tests. It appears clearly that chromosomes are not randomly distributed in metaphase figures of human leucocytes. © 1968 Springer-Verlag.