This study was aimed to investigate the incidence of JAK2V617F mutation in BCR-ABL negative patients with myeloproliferative disorders (MPD) and its relation with clinical characteristics of MPD. The sensitive and specific test for JAK2V617F mutation was established for improving diagnosis level in Gansu province. 47 BCR/ABL negative MPD patients and 12 healthy people were enrolled in this study. Allele specific polymerase chain reaction (AS-PCR) was used to amplify the exon 12 of JAK2 gene which harbours V617F mutation. The PCR products were identified by DNA sequencing. And its relation with clinical characteristics of MPD was analyzed also. The results indicated that the incidence of JAK2V617F positive mutation in 47 patients with BCR-ABL negative MPD was 74.5 % (35/47), including 83.9 %(26/31) in patients with polycythemia vera (PV), 60 % (9/15) in patients with essential thrombocythemia (ET), only in one patient with idiopathic myelofibrosis (IMF). In PV group, the patients with JAK2V617F positive mutation had higher counts of WBC and Plt than patients with JAK2V617F negative mutation. In ET group, the patients with JAK2V617F positive mutation had higher WBC count and Hb level than those in the patients with JAK2V617F negative mutation with tendency of suffering from complications such as hepatosplenomegaly, haemorrhage and thrombosis. It is concluded that JAK2V617F mutation is more frequent in BCR-ABL negative patients with MPD, the AS-PCR method is sensitive and specific for detection of the mutation and may successfully use in clinical examination.