WUHAN -- The "family inn" phenomenon is a growing trend in China where home-owners open their unused properties to short-term lodgers, usually tourists.

The industry has seen explosive growth, according to a report released Wednesday by a branch of China Tourism Association.

The number of family inns on the Chinese mainland has reached about 200,000, a year-on-year increase of 300 percent, with more than 20,000 such businesses established in the southern province of Guangdong alone, the report said.

According to the report, chain stores and a concentration of family inns boost the development of regional tourism markets, which in turn increases the value of the inns themselves.

China's domestic tourism industry earned about 3.9 trillion yuan ($589.5 billion) in 2016, and there are plans to raise tourism revenue to 7 trillion yuan by 2020.

China is working to develop tourism into a major driver of economic transformation. By 2020, investment in tourism is expected to grow to 2 trillion yuan, and the sector will contribute more than 12 percent of GDP growth, according to a State Council five-year tourism plan (2016-2020).