Objective To explore the vitamin K level in Chinese maintenance hemodialysis (MHD) patients. Methods MHD patients and healthy subjects from our outpatient clinic were enrolled from 1 to 30 in March 2016. Demographic data was collected. Fasting serum samples from all subjects were collected for biochemistry tests and the measurement of known vitamin K-dependent proteins, i.e. matrix Gla protein (MGP), osteocalcin (OC) and uncarboxylated osteocalcin (ucOC). We also quantified the fraction of ucOC of total OC (%ucOC). Differences of these parameters between the two groups were analyzed. Results We enrolled 70 MHD patients as a test group and 70 healthy subjects as a control group. There was no significant difference in MGP between MHD group and the control group [(4.1±2.2) vs. (4.4±1.0) pg/mL, P=0.441]. The value of %ucOC was significantly higher in the MHD group than that in the control group [(79.3±19.3)% vs. (51.9±13.0)%, P<0.001]. Conclusions Deficiency of vitamin K appears common in Chinese MHD patients. Besides pathological reasons, dietary habit may also contribute to this phenomenon.