OBJECTIVE: To study the changes and roles of plasma thromboxane A2 (TXA2) and prostaglandin I2 (PGT2) levels and their ratio in Henoch-Schonlein purpura nephritis (HSPN) in children. METHODS: Plasma levels of TXA2 and PGI2 were measured using ELISA in 45 children with HSPN and 20 healthy children. RESULTS: Plasma TXA2 level was significantly higher, while plasma PGI2 level was significantly lower in HSPN children in the acute phase than in the control (P<0.01). The ratio of TXA2/PGI2 in HSPN children in the acute phase was statistically higher than in the control (9.55±3.56 vs 0.87±0.21; P<0.01). In the convalescence phase, plasma TXA2 level remained higher and plasma PGI2 level was elevated and higher than in the control, so the ratio of TXA2/PGI2 was reduced to normal level.CONCLUSIONS: The imbalance of TXA2 and PGI2 may be involved in the development of renal damage in children with HSPN. The balance of TXA2 and PGI2 contributes to renal recovery.