Abstract: Scattering of radar-wave by flunctuations of atmospheric refractivity is studied in this paper. The main results are as follows: In case of intensive atmospheric refractivity flunctuations, the power of back-scattered. radiation due to the refractivity flunctuations may exceed the minimum detectable power of radar, and is of same order of magnitude as the meteorological "angel" wave. With other evidences, it is hence suggested that the scattering by refractivity flunctuations may be an important mechanism in the formation of meteorological "angel" wave. 2. An equation is derived to express the wave magnitude as a function of the distance propagated in the medium with refractivity flunctuations. It is found that the scattering effect does not affect the wave magnitude significantly in general, but it may cause the wave-width to spread when the scale length of refractivity as well as the wave-width of radar are quite small.