The psychometric functions of the 700 most frequently occurring Mandarin monosyllables (whose cumulative usage was 98.38% in 1,125 distinct monosyllables) were evaulated. Twenty normal-hearing subjects were asked to hear and to repeat the 700 monosyllables which were randomly presented at the level from 0 to 55 dB HL in 5-dB step. The psychometric functions for each of the 700 monosyllables were fit with third-degree polynomials. The fitted curves were used to calculate five psychometric characteristics: (1) the threshold at 0% correct; (2) the threshold at 50% correct; (3) the instantaneous slope at 50% correct; (4) the linear slope from 20% to 80% correct; and (5) the intelligibility at the highest presentation level. The mean values of such five psychometric characteristics for 700 monosyllables are 1.1 dBHL, 12.1 dBHL, 4.5 %/dB, 4.1% %/dB, and 93.4%, respectively. With the psychometric characteristics, the 700 monosyllables can be used to create word recognition test lists for different purposes, such as constructing test lists with different homogeneity, different familiarity, or different difficulty; and the recognition performance of test lists will be predictable. Futhermore, the research results also indicated that there is no significant correlation between the psychometric characteristics and the occurring frequences of monosyllables.