The dynamics of microbial oils fermented from corn stover hydrolysate was studied. The mathematic model of thalli growth and microbial oils synthesis during the fermentation of microbial oils changed along with the time was built based on Logistic equation and Luedeking-Piret equation. The test value was validated with the model. The compositions of unsaturated fatty acid in microbial oils were analyzed by the gas chromatography. The results indicated that the corn stover was used as a raw material, mortierella isabellina as a strain, after aerobic intermittent fermentation, the biomass and content of microbial oils reached 10.63 g/L and 49.53% respectively. A good coincidence between models calculation values and experimental data was observed, therefore, the model equations can really reflect the process of the microbial oils fermentation.