Abstract: Juncture in Chinese can be divided into four levels, such as the juncture between phonemes,between syllables, between rhythm units and between stops. Among them, the juncture between phonemes is the strongest, the one between syllables is next stronger and the two others are weaker.In Chinese synthesis systems that use syllables as basic units, the juncture between phonemes has already been saved in syllabic dictionaries. So the juncture between syllables becomes the most important one. In this paper, we research on perception of the juncture between syllables by two perception experiments. Conclusions are:First, listeners are more sensitive to pitch transitions than to formant transitions; Second, listeners who have knowledge of phonetics pay more attentions to formant transitions than others, yet, they can not distinguish the synthetic disyllable-words which have the formant transition sections from those which have no formant transition section in most of the cases:Third, the segment structures between syllables affect the perceptive perceptive sensitivity of formant transitions.the tonal structures affect the sensitivity too.