Astaxanthin, a main carotenoid pigment, has a strong antioxidant activity. A kinetics of astaxanthin fermentation by Xanthophyllomyces dendrorhous was studied in a batch fermentation system. The unstructured models were proposed using the Logistic equation for microbial growth, the Luedeking-Piret equation for astaxanthin production and Luedeking-Piret-like equation for glucose consumption. The production of astaxanthin was partly growth-associated. Compared with the experimental data and calculated data, most of errors were lower than 10 %, it showed that the proposed unstructured models were adequate to describe the fermentation bioprocess of astaxanthin by X. dendrorhous.