Now the amount of antibiotics used in the hospital has reached 35% of the total drug consumption. The extensive usage of antibiotics has not only brought the drug resistance, but also increased the economic burden of patients. How to control the abuse of antibiotics and use antibiotics reasonably has become an urgent problem to be solved. OBJECTIVE: The purpose of this study was to evaluate the efficacy and cost of ceftriaxone?cefotaxime and cefuroxime therapy in patients with moderate lower respiratory tract infection. METHODS:150 patients with moderate lower respiratory tract infection were randomized to receive ceftriaxone(1g .d)?cefotaxime(1g b.i.d) and cefuroxime(o.75g t.i.d).Evaluation of clinical efficacy depended on whether or not clinical findings subsiding?eradication of the initially susceptible and normal outcome of laboratory tests were obtained 7 days after therapy.In the cost analysis we have took the following costs into account:drug cost ?check-up cost ?bed cost ?administration cost?treatment of adverse events and lost income of patients. RESULTS:107 patients were analyzed. The effectiveness rates of ceftriaxone?cefotaxime and cefuroxime arms are 86.21(25/29)?85.37(35/41) and 75.68%(31/38) respectively with no significant difference(P>0.05) ,but their costs are 2931.97±161.84 ?3749.52±215.98 and 3340.56±221.26 yuan(RMB) respectively with significant difference (P<0.05).CONCLUSION: Our pharmacoeconomic analysis demonstrated that of all the three drugs ceftriaxone had the best cost effectiveness, and was a better choice for the treatment of moderate lower respiratory tract infection.