a method for a base station to obtain radio capability information of a user equipment in long term evolution system comprises that : a mobility management entity sends an initial context setup request message to the base station , and the base station determines whether the received initial context setup request message contains an information element of forbidden inter radio access technologies ; when contains , the base station writes the radio access technology types which are not included in the ie of forbidden inter radio access technologies into a query message , and sends the query message to the ue ; otherwise , the base station writes all radio access technologies supported by protocol into a query message and sends the query message to the ue ; after receiving the query message , the ue sends the ue radio capability information of radio access technologies supported by the ue itself to the base station . the above method avoids the blindness of writing query message for the base station , which reduces the overhead of the air interface , thereby shortens the connection delay of the ue in the long term evolution system .