Abstract: [Objective]To characterize the blood biochemistry in peripartum dairy cows with subclinical hypocalcaemia and to provide scientific basis for the early-warning of this disease.[Method]Twenty-eight antepartum dairy cows from a large-scale and intensive dairy farm in Heilongjiang were randomly selected, and the plasma sample of each dairy cow was collected on antepartum week 2 and week 1, and 0, 3, 7, 14 and 21 days after calving and was used to assess the variation characteristics of the blood biochemistry indexes. [Results]The incidence of subclinical hypocalcaemia was 42.9%, and significant lower plasma calcium concentrations was detected in hypocalcaemia group dairy cows from antepartum week 2 to 3 days after calving. There was significant higher level of plasma phosphor on antepartum week 1 and plasma AST on 3 days after calving in hypocalcaemia group dairy cows, and significant lower plasma HDL-C on 7 days after calving. Pearson correlation analysis showed that there was very significant positive correlation of plasma calcium with plasma phosphor, TC, TG, HDL-C and LDL-C in hypocalcaemia group cows, and very significant negative correlation with plasma NEFA and AST. [Conclusion]Antepartum high plasma phosphor was considered as an important factor for occurrence of subclinical hypocalcaemia in this dairy farm, and antepartum lower phosphor feeding should be useful for prevention of this disease.