This paper discusses the property of voicing and releasing in coda stops in Old Chinese, which is of great significance to the phonetic types and historical comparison between Chinese and Tibetan Languages. The nature of Old Chinese is mainly based on the historical comparison between Chinese and Tibetan Languages and Chinese loan words in other languages. For example, in Ancient Tibetan the stop codas were transcribed to voiced letters. The majority of bound function words in Classical Tibetan have two variants based on whether the preceding codas are voiced or not. The /-l(-r)/ coda in the ancient Chinese northern languages and early Sanskrit-Chinese phonetic transcription comes from the /-d/ coda. Old Chinese loan words in Japanese have voiced stop codas. Modern Chinese dialects also have voiced stop codas. In addition, stop codas in Tibetan Xigaze, Balti, Lajiao and other dialects, Xifan yiyu and Qiang languages all have the nature of releasing. The “broken tone” in Chinese is caused by a released glottal stop.