【Abstract】 Objective To investigate the reference interval for CA724 in healthy population in Qinghai. Methods 900 healthy examinees (including urban and rural residents in Qinghai area) in the medical examination center of GradeA Tertiary Hospital in Qinghai from January 2015 to December 2017 were selected. CA724 in the fasting elbow venous blood (5ml) was detected by Roche detection system after incubation for 35min and centrifugation for 10 min. Each detection met the internal quality control standards so as to avoid the systematic errors. Results Wilcoxon rank sum test showed that the difference of serum CA724 between male and female in Qinghai area was statistically significant (U=2082, P＜0.05). KmskalWallisH test showed that difference in CA724 between different age groups was not statistic in male healthy population (H=2161, P＞0.05) and female healthy population in Qinghai (H=1931, P＞0.05). The median CA724 level was 192U/ml for males and 224U/ml for females, the 95th percentile interval of male was 0~1124U/ml, and the 5th percentile interval of female was 0~1285U/ml. Conclusion The establishment of the CA724 reference interval for healthy people in Qinghai should be based on sample size and local actual situation. The subjects should be the local healthy population.