In this paper, we presented a semantic speech segmentation approach, in particular sentence segmentation, without speech recognition. In order to get phoneme level information without word recognition information, a novel vowel/consonant/pause (V/C/P) classification is proposed. An adaptive pause detection method is also presented to adapt to various backgrounds and environments. Three feature sets, which include pause, rate of speech and prosody, are used to discriminate the sentence boundary. Experiments on broadcasting news indicate that the performance of the proposed algorithm is satisfying.