Objective: To reveal the molecular genetics mechanism of a pedigree with hypochondroplasia (HCH) from south China and create the necessary prerequisite of its future prenatal gene diagnosis.Methods: On the base of the clinical diagnosis, PCR-DNA direct sequencing was used to detecte mutation(s) of FGFR3 gene of the patient.After finding c.1135T＞C novel mutation, the pathogenicity of this mutation was identified in detail.The methods include the screening of the 200 homologous chromosomes of 100 cases of healthy control population with denaturing high-performance liquid chromatograph (DHPLC) and allele-specific amplification (ASA) to count the mutation frequency of the site; the conservative analysis of the amino acid at the mutation site in 12 cross species; the harmful prediction of the mutation using bioinformatics software.