Abstract: A total of 106 clones of Picea crassifolia in Longqu P.crassifolia Clone Seed Orchard in Zhangyewere used as materials,and the genomic DNA of P.crassifolia was extracted by improved CTAB method,theSLAF library was constructed and sequenced with high flux,and then the SLAF sequencing data were analyzedand SNP sites were screened,and the clustering of samples was obtained based on adjacency analysisrespectively.The results showed that the efficiency of two terminal alignment was 95.33%,indicated that theSLAF database was successfully established.The Q30 of the sequence measured and the sequencing quality washigh,but the error rate of base sequencing was low.A total of 4 058 883 SLAF tags were developed,and theaverage sequencing depth of the tags was 21.21×.A total of 12 275 765 P.crassifolia SNP markers weredeveloped,and the number of SNPs in each P.crassifolia sample ranged from 1 890 934-4 487 841.Using the developed high quality SNP markers of P.crassifolia,106 phylogenetic trees of P.crassifolia were constructed.It was found that P.crassifolia from different provenances were evenly distributed in each group,and P.crassifolia from different provenances mostly were clustered into one class.By SNP markers and principalcomponent analysis,these clones were more likely to be derived from the same ancestor,indicated that thegenetic relationship between clones was similar.It provids basic data for the analysis of genetic diversity and theconstruction of genetic map in the future,and also provids a basis for the elite seeds selection in P.crassifolia primary seed orchard,and lays a foundation for the construction of high generation seed orchard.