In the context of the new crown pneumonia sweeping the world，many marathons have been cancelled due to the necessity of epidemic prevention and control. The Chengdu Marathon 2020 was successfully held under strict epidemic prevention measures，a reduced scale of participation and a shorter preparation time. This paper briefly analyzes the main sources of commercial value of the 2020 Chengdu International Marathon in the new context of the epidemic impact. The marathon needs to be experienced by the participants themselves，and a large number of interactive opportunities will be generated during the experience，and these opportunities form the commercial value of the Chengdu Marathon. The commercial value of Chengdu Marathon is transformed into event revenue during the operation process，and the event revenue is mainly composed of four parts：registration fees，government subsidies，sponsorship income and derivatives sales. Although the Chengdu Marathon has been successfully held for four years and has grown into a candidate race for the World Marathon Grand Slam League，its operating income is still not enough to cover its running costs. The organizers and operators of the Chengdu Marathon can improve the market-oriented operation of the event from four aspects：cultivating the characteristics of the event，positioning it precisely，strengthening the development of race derivatives，providing race service products，and managing the race copyright as a package，so as to achieve profitability as soon as possible while promoting the development of national fitness.