The acoustic characteristics of voiceless affricates have not been clearly determined. The voiceless affricates /ts/ and /t∫/ in CV syllables are analyzed in this paper to obtain acoustic features useful for their discrimination from the voiceless fricatives /s/ and /∫/ as well as for distinguishing between /ts/ and /t∫/ themselves. The maximum rate of increase in short‐term power at consonantal onset was found to be useful for separating the affricates from the fricatives, while the frequency of the spectral zero, extracted by assuming a model with one zero and two poles for the frequency spectrum up to 7 kHz, was found to be effective for separating the two affricates [H. Fujisaki and O. Kunisaki, IEEE Trans.ASSP‐26, 21–27 (1978)]. Based on these results, a recognition test was carried out on 100 CV syllables consisting of /ts/, /t∫/, /s/, or /∫/ followed by one of the five Japanese vowels uttered by a male speaker, and a recognition rate of 99% was achieved. [Work supported by Ministry of Education Grant‐in‐Aid for Scientific Research No. 239005.]