Xi'an, the capital city of Northwest China's Shaanxi province, is likely to be the next city to announce car sales caps, just a month after Guangzhou launched the restriction.

The local government on August 2 released a traffic policy draft, which includes limitations on new vehicle purchases and control of the frequency with which vehicles can be used, in a bid to ease the heavy traffic flow and environmental problems.

The government asked for comments on the draft from the public until August 15.

If the rules are launched officially, Xi'an will be the fifth city to limit car purchases by clamping down on vehicle registrations, after Beijing, Shanghai and Guiyang, in Guizhou province, and Guangzhou.

Other big cities with worsening traffic and environmental problems, including Shenzhen, Hangzhou, Chengdu, Tianjin and Nanjing, are likely to follow the move.

Analysts said that the implementation of car sales curbs in more cities will impact China's growing automobile industry in the long run.

The shrinking market may bring more challenges to China's struggling domestic auto brands, analysts said.