A velocity/distance detection system that comprises a transmitter and a receiver and is configured to detect a distance between the transmitter and the receiver, wherein the transmitter is configured to determine a time reference point at which respective phases of plural frequency signals are in a predetermined relationship based on the plural frequency signals, and to transmit a composite frequency signal obtained by combining the plural frequency signals after the respective phases of the plural frequency signals are adjusted based on the determined time reference point, and the receiver comprises: a receiving unit (201, 202, 203, 204, 205) configured to receive the composite frequency signal transmitted from the transmitter, a complex-output calculating unit (206, 207A, 207B, 208A, 208B) configured to perform quadrature detection of the composite frequency signal received by the receiving unit with a Doppler effect and propagation delay by reference angular frequencies of at least the same number as that of the plural frequency signals, and to calculate complex outputs for a number of the reference angular frequencies based on a detection output thereof, whereby each complex output represents an amplitude estimate value and a phase estimate value, an operating unit configured to calculate a velocity or a reception angular frequency at which the difference in power estimate values or amplitude estimate values for the number of the reference angular frequencies based on the complex outputs for the number of the reference angular frequencies becomes equal to or less than a threshold, a velocity estimating unit configured to estimate the velocity when the difference becomes equal to or less than the threshold as a velocity of the transmitter or the receiver, and a distance estimating unit (211, 213) configured to extract each phase estimate value of the plural frequency signals from the complex outputs for the number of the reference angular frequencies when the difference becomes equal to or less than the threshold, to calculate a propagation delay time of the composite frequency signal between the transmitter and the receiver based on each extracted phase estimate value, and to estimate the distance between the transmitter and the receiver based on the calculated propagation delay time. a receiving unit (201, 202, 203, 204, 205) configured to receive the composite frequency signal transmitted from the transmitter, a complex-output calculating unit (206, 207A, 207B, 208A, 208B) configured to perform quadrature detection of the composite frequency signal received by the receiving unit with a Doppler effect and propagation delay by reference angular frequencies of at least the same number as that of the plural frequency signals, and to calculate complex outputs for a number of the reference angular frequencies based on a detection output thereof, whereby each complex output represents an amplitude estimate value and a phase estimate value, an operating unit configured to calculate a velocity or a reception angular frequency at which the difference in power estimate values or amplitude estimate values for the number of the reference angular frequencies based on the complex outputs for the number of the reference angular frequencies becomes equal to or less than a threshold, a velocity estimating unit configured to estimate the velocity when the difference becomes equal to or less than the threshold as a velocity of the transmitter or the receiver, and a distance estimating unit (211, 213) configured to extract each phase estimate value of the plural frequency signals from the complex outputs for the number of the reference angular frequencies when the difference becomes equal to or less than the threshold, to calculate a propagation delay time of the composite frequency signal between the transmitter and the receiver based on each extracted phase estimate value, and to estimate the distance between the transmitter and the receiver based on the calculated propagation delay time.