The present invention discloses a method for establishing connections in IP flow mapping update in a HRPD network, comprising steps of: (1) when a PCF receives a request for establishing A8 connections that need to be re-mapped, if determining that there is A8 connection supported, sending an A11-registration request to a PDSN; (2) when the PDSN receives the information on A10 connections in the A11-registration request, if determining that there is A10 connection supported, establishing those A10 connections and sending an A11-registration reply; (3) when the PCF receives the reply message, establishing all the A8 connections corresponding to the A10 connections and sending an A9-connect-A8 to the AN; (4) an AT and the AN releasing and removing the IP flow that can not be mapped to any of the A8 connections or resource reserved by the IP flow according to the A9-connect-A8 received.