Abstract: Objective：To collect families with hereditary dentin disorders in Chinese population and perform analysis on phenotype and disease classification, as well as to screen the mutations on the candidate gene DSPP，and to explore the correlation between gene mutation and phenotype. Methods：Comprehensive oral examination was performed for available affected individuals in collected families with dentinogenesis imperfacta (DGI). Clinical phenotypes and classification diagnosis were analyzed in each family. Genomic DNA was extracted from peripheral blood in all investigated members. Mutations screening was performed by amplifying all coding regions and splicing junctions of DSPP and sequencing the products. The results were analyzed by BLAST searching, combined with GENBANK polymorphisms and mutations database of DSPP. Results：A total of 3 families with DGI were enrolled in the study. One of them presents unique xerostomia phenotype besides the typical clinical features of DGI type Ⅱ (DGI-Ⅱ). Among 3 families, no mutation was found in the DSP region, and a common frameshift mutation c.3546-3550delTAGCAinsG of DSPP was revealed in DPP coding region in two families, which was identical to a previous reported mutation in other family with DGI-Ⅱ. Conclusions：The present study reported a novel phenotype in DGI-Ⅱ, and further suggested that DPP mutations be an important pathogenic factor for DGI-Ⅱ, and that c.3546-3550delTAGCAinsG might be a hot point mutation of DSPP in Chinese population.