Changes in the overall genetic features and metabolic potential of the kimchi-fermenting microbial community were investigated by examining a large pyrosequencing-derived data set, in conjunction with metabolite analysis. The metagenome and metabolites revealed that the kimchi microbiome had high metabolic potential with respect to heterotrophic lactic acid fermentations. Based on the abundances of 16S rRNA genes and the representation of whole-genome sequences in the metagenome, we conclude that active microbial populations in kimchi fermentation were dominated by members of three genera, Leuconostoc, Lactobacillus, and Weissella, which is consistent with many previous results (5, 23, 27). Besides microbial genome sequences, a surprisingly high abundance of phage DNA sequences were identified, indicating that bacteriophages influence the kimchi microbial community and may be a key determinant of kimchi microbial community dynamics. Metagenomic analysis of the kimchi samples over time made it possible to monitor not only microbial community composition but also overall features and the metabolic potential during fermentation. Future analyses of microbial abundances and interactions will likely provide insights into how the kimchi microbial community influences metabolite production and, ultimately, kimchi flavor.