Abstract: In order to improve the diagnosis, treatment, prevention and control of hypocalcemia in cows, in this study, in 2021, the basic situation of representative large-scale pastures, and the incidence, diagnosis plan, treatment plan, prevention and control plan of dairy cow hypocalcemia（including clinical hypocalcemia and subclinical hypocalcemia） were investigated in 15 provinces（cities, autonomous regions） including Hebei Province, Heilongjiang Province, Yunnan Province, Inner Mongolia Autonomous Region, and Beijing City. The results showed that there were 73,448 dairy cows in the investigated pasture, and the total incidence of hypocalcemia was 15.48%（2.90% to 30.20%）. The incidence of clinical hypocalcemia in dairy cows in the surveyed pastures was 3.38%, of which Heilongjiang Province had the highest incidence rate（5.40%）, followed by Hebei Province（4.00%）, Yunnan Province（3.30%）, Beijing City（3.30%）, and Jiangsu Province and Tianjin City（1.00%） had the lowest incidence. The incidence of subclinical hypocalcemia was 12.10%（1.00%-26.90%）, of which Yunnan Province had the highest incidence（26.90%）, followed by Shanghai City（20.50%）, Heilongjiang Province（14.00%）, and the lowest incidence was in Beijing City and Shanxi Province（both 1.00%）. Pasture investigation included that the diagnosis of clinical hypocalcemia in dairy cows was mainly based on obvious clinical symptoms（reluctance to move, alternating hind limb pedaling, hind drive rocking, muscle twitching）, and the diagnosis of subclinical hypocalcemia in dairy cows was mainly based on certain clinical symptoms（unnatural head and neck, mental depression, barely standing but unsteady standing, difficulty moving, wagging gait）. Pasture investigation employed a total of 8 plans for the treatment of clinical hypocalcemia in dairy cows, including intravenous calcium gluconate and oral Bowei calcium. Among them, the cure rate of Plan 6（intravenous glucose 500 mL/day·head, calcium gluconate 250 mL/day·head and camphor 10 mL/day·head） was relatively high（92.36%） and the treatment cost（194.44 Yuan/day·head） was relatively low. Pasture investigation employed a total of 10 plans for the treatment of subclinical hypocalcemia in lactating dairy cows, mainly including oral Bowei calcium, calcium and phosphorus feeding. Among them, Plan 6（intravenous calcium gluconate 200 mL/day·head and calcium stick 100 g/day·head） had a high cure rate（100%） and a relatively low treatment cost（52.00 Yuan/day·head）. Pasture investigation employed a total of 16 plans for the prevention and control of clinical hypocalcemia in lactating dairy cows, including feed addition of anionic salts, feeding management, perinatal health care, urine pH measurement and laboratory blood calcium concentration monitoring, among which Plan 2（feed addition of anionic salts 250 g/day·head, feeding management, perinatal health care, urine pH measurement） and Plan 3（feed addition of anionic salts 250 g/day·head, perinatal care, urine pH measurement） had a lower incidence（both 1.00%） and were less prone to mastitis. Pasture investigation employed a total of 17 plans for the prevention and control of subclinical hypocalcemia in lactating dairy cows, including oral Bowei calcium, feed addition of anionic salts, feeding management, perinatal health care, urine pH valve measurement, laboratory blood calcium concentration monitoring, etc., among which the incidence of Plan 2（feed addition of anionic salts 250 g/day·head, feeding management, perinatal health care, urine pH measurement, laboratory blood calcium concentration monitoring in laboratory） was low（1.00%） and less prone to mastitis. The results suggested that the incidence of subclinical hypocalcemia in dairy cows in China was high, so proper appropriate diagnosis and treatment and prevention and control programs were the key to reducing the incidence of hypocalcemia in dairy cows.