We analyzed the bacterial community of Alaska pollock sikhae, a traditional Korean food made by natural fermentation with Alaska pollock, utilizing pyrosequencing. We fermented the Alaska pollock sikhae at two different temperature conditions (10 °C and 20 °C). Before fermentations, the bacterial community was varied. After fermentations, however, Lactobacillus sakei became dominant. The Alaska pollock sikhae sample before fermentations contained only 2% of L. sakei, but the sample at 6 days after a fermentation at 10 °C comprised 74% of L. sakei (90% at 20 °C).