Japanese companies participating in a major trade fair in Shanghai vowed Monday that they will continue to invest in China despite challenges, including a slowing economy amid a property sector crisis and a harsher business environment for foreign companies.

Tetsuro Homma, head of the Japanese Chamber of Commerce and Industry in China, told reporters that Japanese firms operating in the country are "very much encouraged to further expand their businesses," as Chinese Premier Li Qiang pledged at the opening of the event Sunday to promote the market's opening up.

About 350 Japanese firms accounting for more than 10% of the total participating companies are taking part in the annual China International Import Expo, becoming the biggest group of foreign businesses, added Homma, who also serves as executive vice president of Panasonic Holdings.