Abstract： Objective To assess retrospectively the clinical characteristicsand cell immune function of infections caused by Flavimonas oryzihabitans (F. oryzihabitans). Methods We indentified 11 cases of F. oryzihabitans positive cultures from all microbial cultures collected in our hospital from November 1994 to December 1998. Relevant clinical information was collected, including demographic data, underlying disease, and clinical manifestations of the F. oryzihabitans infections. Minimal inhibitory concentrations (MICs) of 15 antimicrobial agents against the 11 F. oryzihabitans isolates were determined. Cell immune function tests were determined by flow cytometry including T lymphocyte subsets (CD3, CD4, CD8 and ratio CD4/CD8) and NK cells (CD16+56) from peripheral blood. Results Six of these patients with infections caused by F. oryzihabitans were male, 5 were female and the mean age was 47.64 years (range, 5 to 69 years). All but 1 patients had severe underlying diseases. 9 (81.8%) of these patients developed infection while hospitalization and 2 (18.2%) before hospitalization (Cases 2 and 5). 8 (72.7%) of these patients manifested primary F. oryzihabitans bacteremia and one each (9.1%) had pleurisy, soft tissue infection and peritonitis. All these isolates were susceptible to amikacin, gentamicin and ciprofloxacin, but resistance to cefazolin, nitrofurantoin, penicillin and piperacillin. CD3, CD4, CD4/CD8 and CD16+56 value (x±s) of these patients were significatly lower than normal values (P<0.01). The mean time of body temperature fell =37 after antibiotic treatment in these patients was 3.5 days (range, 1 to 6 days). All clinical symptom caused F. oryzihabitans after antibiotic treatment disappeared and all patients recovered. Conclusions Infections caused by F. oryzihabitans was very few clinically, and relative to underlying diseases and the presence of foreign material. Immune function abnormality was among mostly factor for the F. oryzihabitans infections.