Microcellular networks seem to be an answer to the increase of mobile services. So it is necessary to improve the knowledge of propagation in the microcell environment. This paper presents microcellular wide band measurements (at 2.2 GHz) performed in Paris and their analysis. The development, in line of sight and in non-line of sight, of the channel impulse response (CIR) and the delay spread are examined. The diffraction influence on the channel impulse response is also investigated. It is shown that diffraction is not able to explain some of the results and that other phenomenon like scattering, need further investigation.