A method for positioning a mobile terminal, comprising: in response to a first request message transmitted by a Core Network, CN, for positioning of a mobile terminal, transmitting, by a Radio Network Controller, RNC, to a Node B, serving the mobile terminal a second request message for retrieving a number of identifiers of cell portions associated with the mobile terminal in a cell division result, wherein the cell division result comprises a plurality of cell portions obtained by dividing the cell where the mobile terminal is currently located, according to a coverage pattern of an antennas group of the Node B; receiving, by the RNC, an identifier of at least one cell portion associated with the mobile terminal sent by the Node B; and transmitting, by the RNC, to a Stand-alone Serving Mobile Location Center, SAS, a Position Calculation Application Part, PCAP, calculation request message carrying the identifier of the at least one cell portion, to enable the SAS to determine geographical location information of the mobile terminal according to the identifier of the at least one cell portion; characterized in that it further comprises the step: if the RNC receives identifiers of at least two cell portions associated with the mobile terminal sent by the Node B, the RNC transmits to the SAS the PCAP calculation request message carrying the identifiers of the at least two cell portions, to enable the SAS to determine highest one of received signal code power of the at least two cell portions associated with the mobile terminal, and then to calculate difference between the highest received signal code power and the received signal code power corresponding to each cell portion, and to select N cell portions with their differences below a preset threshold, and if value of N is 1, then to determine geographical location information of selected cell portion as the geographical location information of the mobile terminal; and if the value of N is larger than 1, then to determine the geographical location information of the mobile terminal, according to weights of respective selected cell portions and corresponding geographical location information, wherein a selected cell portion with a higher received signal code power has a greater weight, and the sum of the weights of the respective selected cell portions is 1. in response to a first request message transmitted by a Core Network, CN, for positioning of a mobile terminal, transmitting, by a Radio Network Controller, RNC, to a Node B, serving the mobile terminal a second request message for retrieving a number of identifiers of cell portions associated with the mobile terminal in a cell division result, wherein the cell division result comprises a plurality of cell portions obtained by dividing the cell where the mobile terminal is currently located, according to a coverage pattern of an antennas group of the Node B; receiving, by the RNC, an identifier of at least one cell portion associated with the mobile terminal sent by the Node B; and transmitting, by the RNC, to a Stand-alone Serving Mobile Location Center, SAS, a Position Calculation Application Part, PCAP, calculation request message carrying the identifier of the at least one cell portion, to enable the SAS to determine geographical location information of the mobile terminal according to the identifier of the at least one cell portion; characterized in that it further comprises the step: if the RNC receives identifiers of at least two cell portions associated with the mobile terminal sent by the Node B, the RNC transmits to the SAS the PCAP calculation request message carrying the identifiers of the at least two cell portions, to enable the SAS to determine highest one of received signal code power of the at least two cell portions associated with the mobile terminal, and then to calculate difference between the highest received signal code power and the received signal code power corresponding to each cell portion, and to select N cell portions with their differences below a preset threshold, and if value of N is 1, then to determine geographical location information of selected cell portion as the geographical location information of the mobile terminal; and if the value of N is larger than 1, then to determine the geographical location information of the mobile terminal, according to weights of respective selected cell portions and corresponding geographical location information, wherein a selected cell portion with a higher received signal code power has a greater weight, and the sum of the weights of the respective selected cell portions is 1.