Platanus acerifolia pollen is considered an important source of airborne allergens in numerous cities. Pla a 1 is a major allergen from P. acerifolia pollen. The present study aimed to express and purify Pla a 1， and to prepare its monoclonal antibody. In the present study， the Pla a 1 gene was subcloned into a pET?28a vector and transformed into the ArcticExpress? (DE3) RP Escherichia coli host strain. The purified Pla a 1 was then used to immunize BALB/c mice. When serum detection was positive， spleen cells were isolated from the mice and fused with SP2/0 myeloma cells at a ratio of 10:1. Hybridoma cells were screened by indirect ELISA and limiting dilution. Positive cells were used to induce the formation of antibody?containing ascites fluid， and the antibodies were purified using protein A?agarose. The results of the present study demonstrated that recombinant Pla a 1 was successfully expressed and purified， and exhibited positive immunoglobulin E?binding to serum from patients allergic to P. acerifolia. A total of 11 hybridomas that steadily secreted anti?Pla a 1 antibody were obtained and an immunoblotting analysis indicated that all of these monoclonal antibodies specifically recognized the Pla a 1 protein. These results suggested that specific anti?Pla a 1 antibodies may be obtained， which can be used for the rapid detection of Pla a 1 allergens and in the preparation of vaccines against P. acerifolia pollen.