Yes. After my my China/Hong Kong SIM card expired and I wasn't able to top up, I used my regular US Verizon service and could get through the Great Firewall. YMMV, depending on carrier, or if conditions change, etc. However, if you are using WiFi, you can NOT get through, you MUST have a VPN app, such as Express VPN or VyprVPN. As for using a SIM card from any other country, you have to look at each SIM card/carrier to see if it works in China or not.