Objective To evaluate the effects of propofol and isoflurane on the change in periopreative serum IL 6,IL 8,IL 10 and the balance between pro and anti inflammatory cytokines.Methods Twenty five ASAⅡ Ⅲ patients scheduled for esophagus cancer surgery were randomly allocated to one of the two groups: isoflurane group(group I) and propoful group(group P). All patients were premedicated with oral diazepam 5mg and intramuscular atropine 0.3mg . In group P anesthesia was induced with propofol 1 2 mg?kg -1 ,fentanyl 2 ?g?kg -1 ,midazolam 2 3 mg and vecuronium 0.1mg?kg -1 and maintained with propofol 5 10 mg?kg -1 ?h -1 , inhalation of nirous oxide (N 2O:O 2=50%:50%) and intermittent of boluses of vecuronium. In group I anesthesia was induced with 3% 4% isoflurane ,fentanyl 2?g?kg -1 ,midazolam 2 3mg, vecuronium 0.1mg?kg -1 and maintained with inhalation of 50% N 2O and isoflurane (ended tidal isoflurane was maintained at 0.6%) and intermittent boluses of vecuronium. During operation BP and HR were maintained with at ?20% of pre anesthesia level. After operation all patients received PCEA with 0.15% bupivacaine and fentanyl 2?g?ml -1 . Blood samples were taken from internal jugular vein before anesthesia (T 0), at skin incision(T 1), 2h after thoracotomy (T 2), 60min after lung were inflated(T 3),1,4 and 24h after operation(T 4,5,6 ) for determination of serum IL 6,IL 8 and IL 10 concentrations. Results All patients showed significant increases in IL 6, IL 8 and IL 10 levels during thoracotomy (P