Using two transgenic rice (Oryza sativa) plant lines, Zhuanpin 1 and Zhuanpin 8, expressing broadspectrum antifungal proteins and their nontransgenic parent cv.Qisiruanzhan as materials, the chemical composition of straw was analyzed, and the changes of cellulose in different parts of straw were studied by fourier transform infrared spectroscopy (FTIR) and Xray diffractometer (XRD). Infrared absorption spectra of cellulose from leaf blade, leaf sheath, and stem was basically the same in the transgenic vs.nontransgenic rice plants, and the differences of absorption intensity and crystal index (O′KI or N·O′KI) among them were not significant. XRD spectra and cellulose crystallinity (CrI) showed no significant differences either by crystal type or structure between transgenic vs.nontransgenic rice.