Abstract: From June to October in 1996,the situation of giant pandas selection and utilization for one of its main foods—Fargesia nitida was studied in detail in Huanglongsi Reserve and compared with the data obtained from other mountains .Results show as follows:(1)We can divide one year into four periods for giant pandas selection on food,through the analysis of droppings and feeding places monthly.(a) From November of last year to June of next year.the stems of bamboo are the main food of pandas (80%),and the percentage of each age group is:old shoots∶two－year olds∶many－year olds＝1∶2.33∶5.33.(b) The first and second ten days of July are the transition period (In this period,giant panda feeds not only on the stem but also on some new shoots occasionally and the percentage of each age group is:new shoots∶old shoots∶two－year olds∶many－year olds＝1∶1.8∶0.5∶0.8).? From the last ten days of July to the second ten days of September,the giant panda feeds on the new shoots (>75%) and some stems occasionally.(d)From the last ten days of September to October,the giant panda feeds on the leaves and branches as well as a small number of stems.(2)Bamboo plots was set up and Vanderploeg and Scavia selectivity index was used to assess the pandas selection for Faresia nitida,we also compared it with other mountains .The results show that for a long time,the giant panda in different mountains adapts the different species of bamboo,which bring about the difference in their feeding habits.However,there is a general tendency that they always prefer the thick stems and thick shoots,which obey the economic principle.(3)The giant panda in Huanglong prefer the stems (basal diameter>10 mm) and the shoots (basal diameter>10 mm),but refuse to eat the slim stems (basal diameter<4 mm) and the shoots (basal diameter<6 mm).(4)The comparison sample height method was used to study the using rate of bamboo stems eaten by giant panda,the result is 22.825%.