Abstract: In order to grasp the influence of extreme temperature on phenology and carry out fine meteorological services. Based on the climate data of northwest Hunan province from 2000 to 2018 and the phenological data of two kinds of animals （frog and barn swallow）and three kinds of plants （peach, catalpa and walnut tree） in the same period, the characteristics of temperature change and its influence on the phenology of animals and plants were studied by using the methods of linear tendency analysis, SPSS correlation coefficient and scatter diagram analysis. The results showed that the distribution of extreme maximum temperature was high in the middle and low in both sides, the regional difference of extreme minimum temperature was not obvious, and the trend of annual change of extreme maximum and minimum temperature was not obvious. The phenological periods of animals in northwest Hunan province were obviously affected by the lowest maximum temperature. The initial sound（see） stage and the final sound（see） stage both advanced and delayed, the initial sound（see） stage mainly showed an advanced trend, and the final sound（see） stage mainly showed a delayed trend. There was a significant correlation between the animal phenology and the extreme maximum temperature at the time of occurrence and 1~4 months before occurrence. The correlation between plant phenology and extreme maximum temperature was significant, but it was not obvious with extreme minimum temperature; The negative correlation between plant leaf bud opening, leaf spreading, flowering, defoliation and extreme maximum temperature was the main one. It can be seen that the extreme maximum temperature is the key meteorological factor affecting animals and plants in the northwest of Hunan province, and the period of animal activity and flowering of plants are more sensitive to the extreme maximum temperature.

Key words: extreme temperature, phenophase, influence, northwest Hunan province