Also, study travelers are getting younger.

The average age of travelers who took their first study tours overseas stood at 12.1 years old, while the age for first domestic study tourists was 8.8 years old.

More than 70 percent of those who go on overseas study trips enjoy an annual family income above 300,000 yuan, while those in the 150,000-300,000 yuan range, mostly choose domestic trips, according to Ctrip.

Foreign universities' preference for students with academic experiences outside the classroom has also spurred many parents to sign their children up for study tours.

Shanghai, Beijing, Guangdong's Guangzhou and Sichuan's Chengdu are top sources of study travelers, while second-tier cities, especially those in the Yangtze River Delta, northeastern Heilongjiang, Jilin and Liaoning provinces, have seen a rapid growth in the number of study travelers.

About 80 percent of parents want their children to go on the trip without their presence, for budgetary reasons and for their children to learn to be independent, says Ctrip.

International classes, camping, university visits, outdoor challenges, culture and charity experiences are most popular elements on these tours.

Hiking through the Tengger Desert in North China's Inner Mongolia autonomous region and taking care of wild animals in Australia have both become hits with those who booked through Ctrip.

The major domestic online travel agency Tuniu has also seen a surge in bookings of study trips abroad for July and August.

Most of the customers are teenagers, accounting for 74 percent of all bookings, with the majority favoring the US, the UK and Australia, Tuniu reports.

For the youngsters, experiences in prestigious universities, summer camps and cultural exchanges are among the most sought after activities.

For the parents, safety, children's interests, the ratio of travel and learning, as well as quality of the academic institute and faculty are key factors.

About half are open to tours which cost around 20,000-30,000 yuan, and 33 percent of them choose those priced under 20,000 yuan, according to Tuniu.

As for other offerings, Wang Shubo, vice-president of Tuniu, says: "In addition to regular study tours, more custom-made tours are now getting parents' attention."

These products feature optional scenic spots and flexible trip arrangements to ensure freedom and privacy for family travelers.

Now, custom-made study tours to the US on Tuniu's website are popular, says Wang.

According to a study by the New Oriental Education and Technology Group, nearly a third of those who plan to study abroad have done study tours beforehand.

With easier visa policies and increasingly diverse study tours, experts project that the Chinese study tour market for overseas destinations alone is likely to be worth 43.5 billion yuan by 2020.