Abstract: The C-banded karyotype of Heteranthelium piliferum species was studied in a natural population from northwest of Iran using aceto-iron-hematoxilin staining and C-banding technique. Chromosome measurements including long arm, short arm and chromosome lengths, arm ratio index, relative chromosome length, heterochromatin percent per chromosome and per chromosome set were made. It was revealed that the karyotype of this species is symmetric and consists of 7 pairs of metacentric chromosomes. Arm ratio index values ranged from 1.01 in chromosome G to 1.44 in chromosome D. One of the chromosomes had a satellite located on the end of its long arm (chromosome G). The Q genome of this species like A, B, D, S, M and Mt genomes in diploid species of Aegilops-Trticum group, H genome in Hordeum, E genome in Agropyron and R genome in Secale has metacentric or sub-metacentric chromosomes.