The Radar Cross Section (RCS) signature of the chaff cloud in the millimeter wave band is useful in many research fields such as radar countermeasure, target identification and discrimination, and so on. To obtain the RCS of the chaff cloud, practical measurement is an effective method. This paper introduces the design and implementation of a bistatic radar which is used for chaff cloud RCS measurement. The configuration of the radar system and the techniques used in this system, including oversampling, digital down conversion, coherent integration, and interpolation, are discussed. The infield experiment results are presented.