A driving state sharing device that shares driving states of an own vehicle and other vehicles (1d-1h), comprising: a driver state detector configured to detect a driver state of the own vehicle; a traveling position detector configured to detect a traveling position of the own vehicle; a communication unit configured to transmit the driver state and the traveling position of the own vehicle and receive other driver states and traveling positions of the other vehicles (1d-1h); and a driving state presentation unit (28, 29) configured to present the detected driver state and the traveling position of the own vehicle as well as the driver states and the traveling positions of the other vehicles (1d-1h); wherein the driving state presentation unit (28, 29) comprises: a presentation mode selecting unit configured to select presentation modes of the driver states of the other vehicles (1d-1h) based on the driver state of the own vehicle; and a presentation information generating unit configured to generate presentation information in response to the selected presentation modes based on the driver state and the traveling position of the own vehicle and the driver states and the traveling positions of the other vehicles (1d-1h); and wherein contents and a method of presenting the driver states of the other vehicles vary depending on the driver states of the own vehicle and of the other vehicles. a driver state detector configured to detect a driver state of the own vehicle; a traveling position detector configured to detect a traveling position of the own vehicle; a communication unit configured to transmit the driver state and the traveling position of the own vehicle and receive other driver states and traveling positions of the other vehicles (1d-1h); and a driving state presentation unit (28, 29) configured to present the detected driver state and the traveling position of the own vehicle as well as the driver states and the traveling positions of the other vehicles (1d-1h); wherein the driving state presentation unit (28, 29) comprises: a presentation mode selecting unit configured to select presentation modes of the driver states of the other vehicles (1d-1h) based on the driver state of the own vehicle; and a presentation information generating unit configured to generate presentation information in response to the selected presentation modes based on the driver state and the traveling position of the own vehicle and the driver states and the traveling positions of the other vehicles (1d-1h); and wherein contents and a method of presenting the driver states of the other vehicles vary depending on the driver states of the own vehicle and of the other vehicles. a presentation mode selecting unit configured to select presentation modes of the driver states of the other vehicles (1d-1h) based on the driver state of the own vehicle; and a presentation information generating unit configured to generate presentation information in response to the selected presentation modes based on the driver state and the traveling position of the own vehicle and the driver states and the traveling positions of the other vehicles (1d-1h); and wherein contents and a method of presenting the driver states of the other vehicles vary depending on the driver states of the own vehicle and of the other vehicles.