The Raman spectrum of polycrystal 1,3-dimethyluracil (DMU) was obtained and investigated. Ab initio (DFT) calculation (B3PW91/6-31G method) of DMU was performed. And the vibration modes of DMU molecular were analyzed. The results suggest that DMU molecule, as a model compound of bio-base, has some advantages in Raman analysis, such as stronger intensity of marker bands and sharper, clearer bands of double band stretching than uracil's. The ultimate goal of this research is to get large quantity of spectral information of DMU and its cyclobutane dimers, use them as model compounds to research on the Raman characteristics of DNA's or RNA's photodamage. And this work is also an essential supplement to the 1,3-dimethyluracil's Raman study.