The present invention provides a pulse modulating method which ensures demodulation of bit data without being affected by a change in the pulse width and permits high-speed transmission, pulse modulating equipment for the pulse modulating method and pulse demodulating equipment. The pulse modulating equipment divides an input signal into n-bit words and converts it into a pulse unit signal which represents the state of the bit data for each word by time intervals i and j between odd-numbered transitions and between even-numbered transitions. The respective time intervals i and j are free from the influence of the transmission line used, for example, and remains unchanged in the pulse demodulating equipment, so that no demodulation error arises. Further, since the bit data is represented by the time intervals i and j between the odd-numbered transitions and between the even-numbered transitions, the coding efficiency increases, permitting high-speed transmission.