Samsung Pay is a mobile payment system that uses near-field communications (NFC) technology. NFC uses radio waves to transmit data between devices and allows contactless payments to be made.
The China UnionPay network operates China's national inter-bank clearing and settlement system. Over five billion cards have been issued by the network, which reaches all cities and rural areas in China.
The Samsung Pay service will support credit and debit cards from nine banks including China CITIC Bank, China Construction Bank, China Everbright Bank, China Guangfa Bank, China Minsheng Banking Corp. Ltd, China Merchants Bank, Hua Xia Bank , Industrial and Commercial Bank of China and Ping An Bank, and six more banks will be "eventually" be added, Samsung said.
Samsung Pay is currently available on the Samsung Galaxy S7, Galaxy S7 edge, Galaxy S6 edge+ and Galaxy Note5 phones in China, Samsung said.
The move follows a similar agreement between UnionPay and Apple's Apple Pay service, announced in December.
Both services compete with Alipay, a payment service similar to Paypal that is run by Chinese e-commerce giant Alibaba, and WeChat Wallet run by the Chinese WeChat messaging service.
China announced last year that it would open the market for clearing domestic bank card transactions to allow competition from foreign companies including Visa and MasterCard. Previously only UnionPay was allowed to provide clearing service for RMB-denominated bank card payments.