Technical Abstract: Microflora of fruit surfaces has been the best source of antagonists against fungi causing postharvest decays of fruit. However, there is little information on microflora colonizing surfaces of fruits other than grapes, apples, and citrus fruit. We characterized bacterial microflora on nectarine fruit surfaces from the early stage of development until harvest. Identification of bacterial strains was made using MIDI (fatty acid methyl ester analysis) and Biolog systems. Biolog identified 35% and MIDI 53% of the strains; thus, results from MIDI were used to determine the frequency of occurrence of genera and species. Most frequently occurring genera were Curtobacterium (21.31 %), followed by Pseudomonas (19.99 %), Microbacterium (13.57 %), Clavibacter (9.69 %), Pantoea (6.59 %), and Enterobacter (4.26 %). The frequency of isolations of some bacteria e.g. major Pseudomonads, P. syringae, P. putida and P. savastonoi or Pantoea agglomerance tend to decline as fruit developed. As Pseudomonas declined, Curtobacterium became more dominant. The time of isolation was a significant factor in the frequency of occurrence of different bacteria indicating succession of the genera. Nectarine fruit was colonized by species representing some of the best biocontrol agents against postharvest fruit decays, such as P. syringe, P. agglomerans, or Burkholderia cepacia, confirming that resident microflora of fruit is an excellent source of antagonists against fruit decaying fungi.