Based on field observation and measurement of periglacial phenomena, radio-carbon dates and sporo-pollen analysis of the samples from the Diaojiaohaizi section, this paper has inquired into the low temperature fluctuations in the Holocene in Daqingshan Mountains. The researches in the paper come into the conclusions as follows: (1) There are six times low temperature fluctuations in the Holocene including those in 9100 aBP～8800 aBP, 8000 aBP～7800 aBP, 7000 aBP～6900 aBP, 6000 aBP～5800 aBP, 5300 aBP～4700 aBP, and 3100 aBP～2400 aBP. They have extensive regional significance except the 2nd and the 4th fluctuations which are relatively weak and confined to Daqingshan Mountains. (2) Comparing the sand wedge developing conditions of three stages in the Holocenc in Diaojiaohaizi section with the sand (ice) wedge developing conditions in Qinghai-Xizhang Plateau and the environmental conditions in the southern boundary of modern perennial frozen earth area in northeastern China, this paper hold that the annual temperature of the cold stages if the Holocene was only 1℃～3℃ lower than that of today, which is different from the conclusions of other researchers. (3) The characteristics of the sand wedge in Diaojiaohaizi section indicated that the extreme low temperature interval in the cold stages if the Holocene was short, which was only 50～60 years. However, the low temperature intervel indicated by vegetation, paleosoil and archaeological materials was relatively long, which was generally 100～700 years. This is clearly due to the sensitive difference of those proxy data.