Abstract: In order to understand the anatomical differences of floral organ among different blueberry’s cultivars,the anatomical structure of blueberry in petals, filaments, anthers and other flower organs were scanned and observed by electron microscopy with four blueberry cultivars, ‘Berkeley’, ‘Brigitta’, ‘Lexie’ and ‘Bluecrop’. The results showed that the cell sizes of inside petals of different blueberries’ cultivars were different with ‘Bluecrop’（0.003 95 mm²）largest one and ‘Brigitta’（0.002 24 mm²）the smallest one. The epidermal hair in ‘Lexie’ was the densest; that in ‘Bluecrop’ was the sparsest. The tubular structure on the top of mature anther of ‘Berkeley’ was a little crossed, and while it was clearly separated in Brigitte. The pollen grains were tetrad composite pollen with ditch and carving.The stigma morphology of different blueberries’ cultivars was different, relatively flat in ‘Berkeley’ and more gullies in Burguita. The types and numbers of ovules in different blueberries’ cultivars were different. The ovule of ‘Bluecrop’ was inverted ovules, but the others were straight ovules. ‘Lexie’ had the most ovules in all cultivars（30）, ‘Brigitta’ had the least（10）. Therefore, there were differences in flower structures of different blueberries’ cultivars, which could be used as a classification of varieties.

Key words: blueberry, flower, ultrastructure