Abstract: Objective:The reference intervals of plasma prothrombin time(PT), activated partial thromboplastin time(APTT), thrombin time(TT)and fibrinogen(FIB)in healthy adults aged 20 to 79 years of Lianyungang area were preliminarily established.Methods:A total of 2 436 healthy volunteers, including 1 395 males and 1 041 females, aged 20 to 79 from June 2018 to December 2018 were randomly selected.The volunteers were divided into male group and female group according to gender, and into 20 to 29 years old group, 30 to 39 years old group, 40 to 49 years old group, 50 to 59 years old group, 60 to 69 years old group and 70 to 79 years old group according to age.The levels of PT, APTT, TT and FIB in plasma were detected by ACL TOP700 automatic coagulation analyzer and its supporting reagents, and the four reference intervals of plasma coagulation were established according to the recommended methods of CLSI C28-A3 and WS/T 402-2012 "Establishment of Reference Intervals of Clinical Laboratory Test Items" .Results:There was no significant difference in the distribution of PT, APTT, TT and FIB in the plasma of healthy adults in Lianyungang area in terms of gender and age( P>0.05). Therefore, this study established a reference interval for the four terms of plasma coagulation, PT was 10.0 to 13.6 s, APTT was 25.2 to 37.8 s, TT was 11.9 to 17.7 s, and FIB was 2.13 to 4.56 g/L. Conclusion:The establishment of reference intervals of Plasm PT, APTT, TT and FIB in healthy adults in Lianyungang area can provide important reference value for diagnosis, monitoring and prognosis evaluation of clinically related diseases.