A radio communication system comprising: a radio base station apparatus (eNB) comprising: an allocation section that allocates downlink control information to a first control region from the first OFDM symbol to a predetermined OFDM symbol in a subframe, and also allocates, in a specific subframe, downlink control information to a second control region that is frequency-divided with a data region, wherein the specific subframe is a subframe in which a user terminal performs a decoding process in the second control region; and a transmission section that transmits information about the specific subframe, the downlink control information allocated in the first control region and the downlink control information allocated in the second control region, wherein the information about the specific subframe is subframe pattern information indicating the specific subframe, wherein the transmission section further transmits information about resource blocks to configure the second control region to the user terminal by higher layer signals, wherein the radio base station apparatus is configured to set search spaces for the second control region on a per user terminal basis; and the user terminal comprising: a receiving section that receives the information about the specific subframe, the downlink control information of the first control region, and the downlink control information of the second control region from the radio base station apparatus, wherein the receiving section further receives the information about resource blocks to configure the second control region by the higher layer signals; and a decoding section that decodes the downlink control information of the first control region and decodes the downlink control information of the second control region based on the information about the specific subframe and the resource blocks, wherein the user terminal is configured to decode the downlink control information of the second control region by performing decoding in a search space for the user terminal. a radio base station apparatus (eNB) comprising: an allocation section that allocates downlink control information to a first control region from the first OFDM symbol to a predetermined OFDM symbol in a subframe, and also allocates, in a specific subframe, downlink control information to a second control region that is frequency-divided with a data region, wherein the specific subframe is a subframe in which a user terminal performs a decoding process in the second control region; and a transmission section that transmits information about the specific subframe, the downlink control information allocated in the first control region and the downlink control information allocated in the second control region, wherein the information about the specific subframe is subframe pattern information indicating the specific subframe, an allocation section that allocates downlink control information to a first control region from the first OFDM symbol to a predetermined OFDM symbol in a subframe, and also allocates, in a specific subframe, downlink control information to a second control region that is frequency-divided with a data region, wherein the specific subframe is a subframe in which a user terminal performs a decoding process in the second control region; and a transmission section that transmits information about the specific subframe, the downlink control information allocated in the first control region and the downlink control information allocated in the second control region, wherein the information about the specific subframe is subframe pattern information indicating the specific subframe, wherein the transmission section further transmits information about resource blocks to configure the second control region to the user terminal by higher layer signals, wherein the radio base station apparatus is configured to set search spaces for the second control region on a per user terminal basis; and the user terminal comprising: a receiving section that receives the information about the specific subframe, the downlink control information of the first control region, and the downlink control information of the second control region from the radio base station apparatus, wherein the receiving section further receives the information about resource blocks to configure the second control region by the higher layer signals; and a decoding section that decodes the downlink control information of the first control region and decodes the downlink control information of the second control region based on the information about the specific subframe and the resource blocks, a receiving section that receives the information about the specific subframe, the downlink control information of the first control region, and the downlink control information of the second control region from the radio base station apparatus, wherein the receiving section further receives the information about resource blocks to configure the second control region by the higher layer signals; and a decoding section that decodes the downlink control information of the first control region and decodes the downlink control information of the second control region based on the information about the specific subframe and the resource blocks, wherein the user terminal is configured to decode the downlink control information of the second control region by performing decoding in a search space for the user terminal.