Taobao, China's largest online retail site, has joined the fight against scalpers at hospitals by adding a free online appointment service.

The service, which started this week, allows registered users to book appointments with 70,000 doctors at more than 600 hospitals in 18 provinces and municipalities, including Beijing and Shanghai.

A user simply needs to click the hospital registration service tag at life.taobao.com and select the region, hospital, department and time, as well as the doctor they want to visit. These appointments can be made one day to two weeks in advance, depending on the clinic.