The airline plans to use the Boeing 787-8 Dreamliner for the service, if it is approved by the Department of Transportation.
The flights to Chengdu -- China's fourth-largest city -- would be available three times a week. United said Thursday that the nonstop flight would be almost four hours shorter than the typical travel time between San Francisco and Chengdu.
This would be the ninth location in the Asia-Pacific region to have United nonstop service from San Francisco, if approved.
United started its mainland China nonstop service in 1986.
Shares of United's parent, United Continental Holdings Inc., added 79 cents, or 2.8 percent, to $28.72 in midday trading. The stock has traded in a 52-week range of $17.98 to $36.74.