Objective To investigate the differences in bacteria distribution and drug resistance of pathogens in patients with lower respiratory tract infection between respiratory general wards and respiratory intensive care unit ( RICU) .Methods All the clinical isolates fromsputumor secretion of lower respiratory tract from2007. 1-2010. 10 were analyzed retrospectively. Antibiotic susceptibility was tested by Kirby-Bauer method. Results The total number of isolated strains was 3202. Among 1254 strains isolated from respiratory general wards, Gram-positive bacteria accounted for 2. 63% , Gram-positive bacteria accounted for 42. 42% , and fungi accounted for 54. 95% . Streptococcus pneumoniae ranked first place among Gram-positive bacteria, accounting for 51. 52% . Haemophilus parainfluenzae bacillus ranked first place among Gramnegative bacteria, accounting for 21. 99% . Both were sensitive to the most commonly used antibiotics. Among 1948 strains isolated from RICU ward, Gram-positive bacteria accounted for 4. 52% , Gram-positive bacteria accounted for 37.73% , and fungi accounted for 57. 75% . Staphylococcus aureus ranked first place among Gram-positive bacteria, accounting for 52. 27% . Acinetobacter baumannii ranked first place in Gramnegative bacteria, accounting for 27. 35% . Both were resistant to most commonly used antibiotics. Pseudomonas aeruginosa had a higher rate of infection both in the general wards and RICU, and was resistant to most commonly used antibiotics.Conclusions In lower respiratory tract infection of respiratory general ward, Gram-positive bacteria with Streptococcus pneumoniae mainly and Gram-negative bacteria with Haemophilus parainfluenzae mainly are both sensitive to the most commonly used antibiotics. While in the RICU ward, Gram-positive bacteria infections with Staphylococcus aureus mainly and Gram-negative bacteria infections with Acinetobacter baumannii mainly are both resistant to most commonly used antibiotics.