OBJECTIVE To find out about the situation of lower respiratory tract nosocomial infection in old patients . METHODS To investigate 237 cases with nosocomial infection of lower respiratory tract who were over 60 years old in our hospital. RESULTS People who were over 60 accounted for 85.25% among the cases with the nosocomial infection of lower respiratory tract, their death rate was 25.74%; in the results of pathogen culturing , Gram-negative bacilli occupied the main position which accounted for 57.81%. Pseudomonas aeruginosa accounted for 35.93% and fungi accounted for 21.88%, they were the two kinds of common pathogens. CONCLUSIONS The serious underlying diseases in old patients, their long hospital stays and weak immune function , large number of invasive diagnostic procedures and traumatic operation, and unreasonal use of antibiotics have made great distribution to nosocomial infection and influence to prognosis, it is necessary to take corresponding measures to settle them.