A vehicle position detection system capable of detecting a position of an own vehicle, comprising: a GPS receiving part mounted on the own vehicle that receives GPS signals from a GPS satellite and comprising a GPS position measuring part for calculating the position of the own vehicle based on the GPS satellite signals, an inertia navigation system for estimating the present position of the own vehicle based on a yaw rate value and a vehicle speed value, a light beacon communication means mounted on the own vehicle and designed for receiving light beacon information from a light beacon arranged in front of an intersection, and a central processing unit mounted on the own vehicle for correcting a position of the own vehicle based on the light beacon information upon reception of the light beacon information from the light beacon communication means, wherein the central processing unit is designed for calculating the position of the own vehicle based on a self-contained navigation, using position measured coordinates of the light beacon included in the received light beacon information which become base point, within a predetermined condition, and for calculating the position of the own vehicle based on GPS signals received by the GPS receiving part outside the predetermined condition, characterised in that the predetermined condition is defined by a combination of: a fixed time (ΔT) from a received time of the base point measured coordinates included in the light beacon information; a fixed distance (ΔL) from the position measured coordinates of the base point; and the set of change of advancing direction and advancing direction changing angle; wherein the number of change of advancing direction relates to change of advancing direction at a predetermined angular velocity for two or more seconds, wherein the advancing direction changing angle relates to a cumulative value of absolute values of transition angles per respective one times, and wherein an origin of the number of change of advancing direction and the advancing direction changing angle is measured coordinates which become a base point obtained from the light beacon information. a GPS receiving part mounted on the own vehicle that receives GPS signals from a GPS satellite and comprising a GPS position measuring part for calculating the position of the own vehicle based on the GPS satellite signals, an inertia navigation system for estimating the present position of the own vehicle based on a yaw rate value and a vehicle speed value, a light beacon communication means mounted on the own vehicle and designed for receiving light beacon information from a light beacon arranged in front of an intersection, and a central processing unit mounted on the own vehicle for correcting a position of the own vehicle based on the light beacon information upon reception of the light beacon information from the light beacon communication means, wherein the central processing unit is designed for calculating the position of the own vehicle based on a self-contained navigation, using position measured coordinates of the light beacon included in the received light beacon information which become base point, within a predetermined condition, and for calculating the position of the own vehicle based on GPS signals received by the GPS receiving part outside the predetermined condition, characterised in that the predetermined condition is defined by a combination of: a fixed time (ΔT) from a received time of the base point measured coordinates included in the light beacon information; a fixed distance (ΔL) from the position measured coordinates of the base point; and the set of change of advancing direction and advancing direction changing angle; wherein the number of change of advancing direction relates to change of advancing direction at a predetermined angular velocity for two or more seconds, wherein the advancing direction changing angle relates to a cumulative value of absolute values of transition angles per respective one times, and wherein an origin of the number of change of advancing direction and the advancing direction changing angle is measured coordinates which become a base point obtained from the light beacon information. a fixed time (ΔT) from a received time of the base point measured coordinates included in the light beacon information; a fixed distance (ΔL) from the position measured coordinates of the base point; and the set of change of advancing direction and advancing direction changing angle; wherein the number of change of advancing direction relates to change of advancing direction at a predetermined angular velocity for two or more seconds, wherein the advancing direction changing angle relates to a cumulative value of absolute values of transition angles per respective one times, and wherein an origin of the number of change of advancing direction and the advancing direction changing angle is measured coordinates which become a base point obtained from the light beacon information.