Background: The COVID-19 pandemic has affected all sectors of the economy and society. To understand the impact of the pandemic on firms in China and suggest responding public policies, we investigated firms in Guangdong Province (a Province with the highest Gross Domestic Product in China). Methods: The survey sample included 524 firms in 15 cities in Guangdong Province. We chose these firms from list published by the government, considering the industrial characteristics of Guangdong province and firm size. The questionnaire comprised of four categories and included 17 questions was developed based on previous studies carried out by OECD. The executives of firms were contacted by phone or WeChat, and were invited to answer self-administered questionnaires through an on-line survey platform. The data was analyzed by SPSS.Results: The following findings are worth to be noticed: (1) 48.7% of firms maintained stability, and 35.1% of the firms experienced a halt in operation or faced closure; (2) Nearly 70%-90% of the firms are or are willing to transform to online marketing, remote office work, and digital operations. (3) 46% of firms believe that there will be a certain loss this year, and 83.5% expected a decreasing trend of the city's GDP growth.Conclusions: firms in Guangdong Province have faced great challenges in the epidemic. The firms’ production and operation activities are limited, and risks are faced. It is necessary to effectively implement supporting policies to profoundly lower production costs for firms, and help firms survive the difficult period, and even gradually transit to normal business operation status.