Objective To investigate the level of serum lipoprotein-associated phospholipase A2(Lp-PLA2) activity in healthy adults of Changsha area and establish the reference interval of serum Lp-PLA2activity. Methods A total of 424 healthy adults (175 males and 249 females) were classified into five groups by different age, including 20 to 29, 30 to 39, 40 to 49, 50 to 59 and over 60 years old group. Serum Lp-PLA2activity was measured by continuous-monitoring assay. According to the requirements of Clinical and Laboratory Standards Institute (CLSI) C28-A3, the reference interval of Lp-PLA2activity was established by nonparametric method.Results The levels of serum Lp-PLA2activities in both males and females showed normal distribution. The average of Lp-PLA2activity was (478± 135)U/L in 175 males and (402±116)U/L in 249 females with statistically significant difference (t＝6.184, P＜0.01). Z test result showed Z＞Z?, so the reference intervals of males and females were established respectively. There was no statistical difference of Lp-PLA2activities among the varied groups of males (F＝1.259, P＝0.288), but there were statistical differences among the varied groups of females (F＝9.341, P＜0.01). The females of the age over 40 years old showed higher activities than those of age under 40 years old (t＝5.732,P＜0.01). However, there was no statistical significance of serum Lp-PLA2activities in the females between the two groups of the age under 40 and the three groups of age over 40. Therefore, the reference intervals of serum Lp-PLA2activities in healthy adults were established as followed: 217-761 U/L for males, 168-566 U/L for the females of 20 to 39 years old and 203-702 U/L for the fe-males of 40 to 86 years old. Conclusion The reference interval of serum Lp-PLA2activity in physical examination of healthy adults in Changsha area was established.