The fermentation process for producing undecane dicarboxylic acid from tridecane, which includes gas-oil-water-cell four phases (two-liquid-phase), was studied. The metabolic characters of the cell growth phase and the production phase of the process were analyzed. It was proposed that cell growth can be identified by the carbon dioxide production rate (CPR) before the production phase. The kinetic models of both the cell growth phase and the production phase were established, respectively. The parameters of the models have been estimated by regression. The calculated curves fit the experimental data very well. The average deviation between those over the cell growth phase and the production phase are 2.4% and 3.6%, respectively.