In order to improve energy efficiency and to relieve shortage of fossil energy and environmental problems, a biogas combined cooling heating and power (CCHP) system driven by internal combustion engine was designed, and its energy flow was presented. As a case study, the biogas CCHP system for a hotel in Beijing, about 10000m2, was analyzed and compared in two operation modes: following the electrical loads (FEL) and following the thermal loads (FTL). The equipment configuration, fuel consumption and supplementary power and the energy, economic and emission performances were calculated and compared in the two operation modes. The results indicate that the primary energy rate (PER) of the CCHP system in FEL is 4.3% higher than in FTL; the investment payback period is 1.4 years shorter; and the CO2 emission reduction is 254.9t less. The biogas CCHP system in FTL has more environmental benefit and in FEL is more efficient and economical.