【Objective】Banana(Musa spp.), origined from the southeast Asia, is the forth food crop in the world, which are important staple food and income-generating crops, especially to the people in the tropical and subtropical regions Therefore, global banana production plays an important role in dealing with the problems derived from the global warming and the population expansion of the world. However, there are some problems exsiting in banana genetic improvement due to uncertainty of ploidy of varieties or breeds. The accurate determination of banana ploidy level is important for proper genetic manipulation and is a prerequisite for interspecific hybridization. So far, various methods, including conventional breeding, genetic transformation, morphological classification, cytological study, biochemical means and molecular markers, have been used to genetically manipulate bananas so as to improve its production. Chromosome counting is tedious and laborious to determine the ploidy of bananas. Flow cytometry(FCM) was employed to detect the ploidy of bananas in this study. 11 banana varieties, named Musa AAA Cavendish Honghe Ai, M. AA acuminateLingshui YeshengJiao, M. balbisianaShixing BB,Red banana, M. ABB CavendishDongguan Zhongba Dajiao,Pisang Ceylan(AAB),FHIA-18(AAAB),Cachaco (ABB),FHIA-17(AAAA),FHIA-03(AABB) andTMB*5259-1(ABBB) were chosen as materials. 【Methods】Approximately 0.5 cm~2 of fresh leaves were chopped with a sharp razor blade in a plastic Petri dish containing 2 mL HRA buffer for each sample. The suspension of nuclei was filtered through a 30 mum nylon mesh to remove large cellular materials. After that, the nuclear DNA of the sample was stained by adding 1 600 muL of 0.02 g·L~(-1) propidium iodide. The sample was mixed gently and incubated briefly on ice before mixing again. A known diploid wild banana germplasm resource, M. AA acuminateLingshui YeshengJiao, was used to test the standardisation of flow cytometry by using a Partec CyFlow? Space Flow Cytometer with a 405 nm laser. At least 5 000-10 000 nuclei were analyzed for each sample. Three leaf samples were tested from each of four plants of each accession.【Results】The FCM was successfully used to analyze the ploidy of 11 banana germplasm resources in present study,. The ploidy of 11 banana clones were divided into four groups. The first group included M. AAA CavendishHonghe Aiand M. AA acuminate.Lingshui YeshengJiao, identified as 2 N. The second group contained M. BB balbisiana Shixing BB, M. ABB CavendishDongguan Zhongba Dajiao,Pisang CeylanandFHIA-18, identified as 3 N. The third group consisted ofCachacoFHIA-17FHIA-03andTMB*5259-1, identified as 4 N. The fourth group only includedRed banana, which showed two peak values in the analysis atlas, 52.79 and 103.24, with good repeatability. Our study had some different results from the prevous research. M. AAA CavendishHonghe Aipreviously was classified as triploid, M. BB balbisiana.Shixing BBas diploid,FHIA-18as tetraploid, andCachacoas triploid,, they were found to be diploid, triploid, triploid and triploid, respectively, in our study.【Conclusions】The ploidy of 11 banana varieties were identified by means of the FCM method and were divide into four groups.Red bananamight be a mixoploid derived from two diploid and tetraploid, and this needs further investigation to confirm.