Abstract: The chromosome number of hybrid Rumex K-1 and its male parent Rumex tianschanicus in Tianshan Mountain were studied. The results indicated that the chromosome number of Rumex K-1 was 2n=60. The chromosome number of its female parent Rumex patientia L. was 2n=60 and that of its male parent Rumex tianschanicus was 2n=20. The karyotype formula of Rumex tianschanicus was 2n=18m（2SAT）＋2sm. The analysis at chromosome level showed that Rumex K-1 had a closer genetic relationship with Rumex patientia L. and a far genetic relationship with Rumex tianschanicus.