Objective:To investigate the family history of congenital heart disease (CHD) in Chogqing for studying the genetic relation of CHD families. Methods:The materials were collected from the population survey about families with more than one members being CHD patients. Map pedigrees for high-risk families were made. The probands and the first and second grade relatives were asked to fill in questionnaires and the high-risk families were analyzed. Results:In the survey of 4387 families

there were 21 high-risk families in which the disease types of the relative patients were inconsistent with those of the probands

the coincidence being 33.33%(7/121).The incidence rates of the first and second grade relatives were 16.49%(16/78)

1.89%(5/265) respectively and their difference was significant ( χ 2=27.73

P <0.001).The inheritance way of high-risk CHD was analyzed by Emery AEH segregation analysis.The result was in accordance with autosomal dominane monogenic inheritance(AD).But the number of sibling was not in the matural state so it was not in agreement with the fact.Autosomal recessive inheritance was difficult to be predicted because few family samples remained and Y-lined inheritance were not in accordance with the actual investigation

so sex-linked inheritance could be excluded.Conclusions:The CHD family investigation of Chongqing region does not show the regional difference but shows family aggregation.The incidence rate of the relatives is related to the extent of the relation.The higher the extent of the relation to the proband

the higher the incidence rate.At the same time

because our investigation are undertaken in the families with single child or twins

which are not in accordance with the natural state

it brings new problems to genetic epidemiology and new methods for clinical application are needed.