按正常的读音规律 ,古溪母字在现代汉语方言中当读k 或t ,可大部分古溪母字在今天的广州粤语中却读为h 、f ,少数字读作零声母音节 ,规律十分整齐。其实这是声母的一种音变现象 ,在粤语范畴内 ,这一声母的音变十分普遍。本文以多点粤语材料作类比 ,通过比较、分析 ,以企证明两个问题 :一、促使粤语溪母字声母产生这一音变的基本原因是轻塞音声母送气成分的作用 ;二、粤语溪母字今天分别读作h 、f 与零声母音节的具体音变条件与音变过程 According to the normal law of pronunciation, the ancient capital of the mother tongue in modern Chinese dialects when reading k or t, most of the Gu Xi mother word in today’s Guangzhou Cantonese but read as h, f, a few digits read as zero-syllables, the law Very neat. In fact, this is a consonant sound change phenomenon, in the Cantonese context, the initial sound is very common. In this paper, a multi-point Cantonese materials for analogy, through comparison, analysis, enterprises to prove that the two questions: First, to promote the Cantonese Xidiao initials sound the basic reason for this is the light component of the sound consonants; Second, Cantonese Xixi words were read today as h, f and the specific sounding conditions and the process of sound change