This study investigated the effect of upland crop rotation on soil bacterial community in bulk soil and rice straw residues in the
alluvial soils. Soil samples and rice straw residues in two crop rotation models including triple rice and rice-upland crops were
collected for incubation under anaerobic and aerobic conditions. Data were analyzed from Denaturing Gradient Gel Electrophoresis band patterns. The results showed that the composition and diversity of communities colonizing the rice straw residues differed from those inhabiting the bulk soil. The bacterial community composition and diversity were only moderately affected by rice straw residues in the bulk soil. Especially, this study indicated that the composition of the bacterial community associated with the bulk soil and rice straw residues was dynamic in two incubation conditions (aerobic or anaerobic) and the different crop rotation models. The findings of this study demonstrated that the bacterial diversity was not affected by the difference incontinuous paddy rice cultivation compared to the upland crop rotation system.