Etimicin sulfate compared with Netilmicin sulfate in treating infection of lower respiratory tract were evaluated. Naive patients and some who have ever used antibiotic but without effectiveness (n=64) with lower respiratory tract infections were selected. They were randomly divided into two groups, one group was given etimicin sulfate, the other were given netilmicin sulfate. Results: Efficacy rates of etimicin sulfate group and netilmicin sulfate were 87.5% (28/32) and 90.6% (29/32); bacterial clearance rates were 87.5% (21/24) and 83.33% (20/24); and adverse drug event rates were 6.35% (2/32) and 3.12% (1/32) respectively. No significant differences was noted between etimicin sulfate and netilmicin sulfate groups. Conclusion: In treating infection of lower respiratory tract, etimicin sulfate displayed a good therapeutic efficacy, safe, low adverse drug reactions and could eradicate many kinds of bacteria, and comparable to that of netilmicin sulfate.