One of the abundant biomass for bioenergy production is thought to be agricultural by-products produced annually. The purpose of this study were to provide basic information about the changes of the moisture contents and chemical compositions for storage periods and bale types of rice straw, and it was attempted for the first time. The bale types of rice straw which were harvest in October 2011, were the square bale, the round bale, and the wrapped round bale type with plastic, respectively. Each of bale were stored in house, outdoor, and rain sheltering facilities condition for 1 year. The moisture contents and chemical compositions for each bale type are investigated for the 3-storage stages (0, 6, 12 month). While the moisture contents of the square and round bales stored in house condition were ranged from 20~25%, the square bale stored under the rain shelter facilities was showed the lowest moisture content less than 20% during the storage periods. For the chemical compositions, the cellulose and hemicellulose contents of rice straw bale stored in outdoor condition were decreased with the storage periods. However, in house condition, the chemical compositions of the square and round bales were slightly increased at the middle and the end of storage stages (6 and 12 months) compared with the initial storage stage (0 month). In conclusion, while optimum and favorable storage conditions of agricultural by-products is a house storage of the bale with plastic, if the bale can stored at outdoor, water penetration prevention such as the rain shelter facilities is required.