Objective To understand the house-dust mite fauna in the school dormitory in Guangzhou city.Methods With the direct smear method and saturation solution of NaCl floatation method,a total of 970 bed-dust samples collected from the five school dormitory buildings were examined,from Oct.to Dec.in 2006.The house-dust mite in the samples were counted and classified.Results The prevalence rate of mite was 98.76%.About 72% of the samples,the number of mites was 500 and 3 000/g dust.Mean number of the mites in bed-dust samples showed a significant difference between the male and female student dormitory,and among five dormitory buildings.The mean number of mites usually decreased as the floor increased.Dermatophagoides pteronyssinus,Dermatophagoides farinae,gamasid mites,scab mites and pyemotidae etc were found in the samples.Conclusion House-dust mites universally exist in bed-dust of the school dormitory in Guangzhou city and the number is larger.Dermatophagoides pteronyssinus,Dermatophagoides farinae are the dominant kinds among the mites.