Objective To investigate air bacteria pollution and the rule of microbes spread in some markets in Guangzhou, aiming at prevention and forecast airborne pathogenic microbes. Bacteria and Staphylococcus aureus were collected to provide reference on evaluation and of the spread of through the air in public. Methods Gravity exposure of microbial media plates was used to sample the airborne bacteria in eight different markets in Guangzhou on a given day, from 2003 to 2005. The simulated experiment in the laboratory was conducted based on the results of natural sampling stations. Results Samples taken at different times showed wide variations with quantities of airborne bacteria (total count) and Staphylococcus aureus ranged from 95 to 1.5?104 cfu per petri dish and from 2 to 1.2?104 cfu per petri dish respectively. Movement of airborne bacteria in the market obeyed quadratic equation pattern. The spread distance of airborne bacteria was among 24 to 26 meters. Maximum airborne bacteria were detected from 17:00 o'clock to 19:00 o'clock in a day. Conclusion The count of market airborne bacteria is markedly more than the limits stipulated in the related national standard GB 9670-1996. Live fowls sold in the markets are the main carriers of bacteria and the potential pollution resource of pathogenic bacteria.