In this study

the karyotype of Fasciolopsis buski has been investigated by the air drying method. The results show that the diploid number of chromosomes is 2n =14. The means and standard deviations of the relative lengths

arm indices and centromeric indices of the chromosomes have been calculated. According to the nomenclature recommended by Levan et al (1964)

the karyotype of F. buski obtained consists of one pair of large-sized metacentrics (m)

2 pairs of medium-sized metacentrics (m)

one pair of medium-sized submetacentrics (sm)

one pair of small-sized metacentrics (m)

one pair of small-sized submetacentrics (sm) and one pair of small-sized telocentrics (t).Idiogram of chromosomes has been constructed from measurements of 19 good metaphase spreads in mitoses.The karyotype of F. buski of this paper is compared with that reported by Gao et al (1952). Statistically

there are very distinct differences (p<0.01) of the means of the arm indices and centromeric indices of the 3rd

4th and 6th pairs of chromosomes between the two results. Basing on the arm indices and centromeric indices of these chromosomes calculated by us

the 4th and 6th pairs of chromosomes are submetacentrics while Gao et al (1952) considered that these 2 pairs of chromosomes are all metacentrics