Alibaba.com ended its partnership with PayPal, the online payment unit of Ebay Inc, last month after PayPal wanted to increase transactions for certain accounts.
Under the deal with Western Union, users buying items on AliExpress will be allowed to make cash payments through Western Union Agent locations in more than 160 countries.
Alibaba.com is a unit of Alibaba Group, which is about 40 percent owned by Yahoo Inc.