Abstract： The advances of solid state negative-resistance devices, such as tunnel diodes, variable reactance semiconductor diodes used in parametric forms, lead to the interests of the study of periodically loaded travelling type distributed amplifiers. This paper gives a detailed analysis on the transmission characteristics of this type of microwave amplifier. The analysis includes the study of the phase equation, gain equation, the frequency-phase characteristics, the pass band vs stop band relationships and the phase velocity and group velocity characteristics. A detailed analysis on the travelling wave type semiconductor diode parametric amplifier is also given. Important universal curves and design conditions are also included for ready references.