Abstract: The compositions of bark fiber in 64 samples (2-3 year old branches) of wild Pteroceltis tatarinowii population in Daguisi National Forest Park,Hubei province were analyzed.Results showed that the average value of moisture,ash,cold water extraction,and hot water extraction was 8.267%,6.273%,24.025%,and 26.594%,respectively;of 1%NaOH extraction,benzene-alcohol extraction,holocellulose,and acid accumulator insoluble lignin was 60.904%,11.011%,56.759% and 9.698%,respectively;cellulose absorbance value was 0.373.The distribution of four indices,namely acid accumulator insoluble lignin,ash,cellulose absorbance,and 1%NaOH extraction,was near to normal distribution,but other variables had large skewness.The inter-correlations between moisture and 1%NaOH extraction,ash and acid accumulator insoluble lignin,holocellulose and acid accumulator insoluble lignin were significant (p < 0.05). The inter-correlations between moisture and ash,moisture and hot water extraction,moisture and holocellulose, benzene-alcohol extraction and holocellulose,benzene-alcohol extracts and acid accumulator insoluble lignin were highly significant (p < 0.01).The 64 samples could be divided into 23 groups with average linkage of 5.627,which showed high phenotypic diversity in the wild Pteroceltis tatarinowii population in Daguisi National Forest Park and its broad prospect of genetic improvement.