Objective To explore the influence of hemodialysis (HD) on the expression of inflammation marker lipoprotein-associated phospholipase A2 (LpPLA2) in end stage renal disease (ESRD) patients, we evaluated their changes in LpPLA2 activity and C-reactive protein (CRP) concentration before and after HD. Methods We observed 20 ESRD patients on HD, from whom 8ml peripheral blood were taken just before HD, after 2 h during HD, and immediately after HD. C-reactive protein was estimated by turbidometric assay, and LpPLA2 activity was measured by enzyme-linked immunosorbent assay (ELSA). Result In ESRD patients before HD, CRP concentration was higher than normal controls (P＜0.01), but LpPLA2 activity was indifferent from the controls (P＞0.05). In ESRD patients after a HD session, CRP concentration did not change significantly (P＞0.05), as compared to that before HD and after 2h during HD. However, LpPLA2 activity increased greatly after 2h during HD and after a HD session (P＜0.01), as compared to that before HD. Conclusion Hemodialysis can induce microinflammation in ESRD patients. This pro-inflammatory state may be introduced partially by the increase of LpPLA2 activity.