A family poses for a picture on a section of the Great Wall in Beijing. [Photo/China Daily]

The number of family travelers increases with the mercury as students enjoy a summer break every year.

Family packages account for over 40 percent of all bookings through China's biggest online travel agency, Ctrip.

The second-child policy introduced in January 2016 has expanded the market, the agency says in a report issued earlier this month.

Orders from families traveling with two children increased 14 percent.

Families' spending averages about 10,000 yuan ($1,470), 15 percent more than adult travelers'.

Shanghai, Beijing and Guangdong province's capital, Guangzhou, produce the most family travelers, respectively. Hainan province's Sanya, Fujian province's Xiamen and Beijing are their favored domestic destinations.

Singapore, Thailand's Phuket Island and Japan's Osaka are the most popular outbound destinations among family travelers.

Parents tend to spend more to ensure their whole family can enjoy quality dining, accommodation and fun experiences, Ctrip says.

Families with children ages 5 to 6 prefer zoos, botanical gardens, ocean parks and interactive do-it-yourself experiences to satisfy kids' curiosity, Beijing-based mobile data-service platform TalkingData says.

Museums and historical sites are usually included in long-distance trips for older children because of their educational value.

Children around 5 or 6 are taken on five to 10 trips annually - the most frequently of all comparable age ranges, TalkingData reports.

Parents usually take children younger than 4 on short sightseeing trips to expose them to nature.

Customized tours have grown increasingly popular. The number of Ctrip's tailored trips for families has tripled over the past year.

"Customized tours can satisfy the very complex and specific needs of parents and children travelers," says Shi Yuzhuan, chief marketing officer with Ctrip's tourism division.

The most common benefits are that such tours can help customers conveniently find such things they may suddenly need as baby bottles or pediatric medicines, Shi says.

"Customized tours are private and offer better service," Shi says.

"That makes them better for family travelers."