The invention provides a fetal concentration quantification method and device and a fetal
genotyping method and device. The fetal concentration quantification method comprises the following steps: acquiring
sequencing data containing a plurality of SNP sites; recording the
mutation frequencies of all SNP sites in the
sequencing data, and classifying the SNP sites with the
mutation frequency of 1%-25% into a first type of frequency, and classifying the SNP sites with the
mutation frequency of 75%-99% into a second type of frequency, wherein the second type of frequency is equal to 1-
mutation frequency; calculating a median or a mean value of a
data set formed by the two frequencies, wherein the median or the mean value is twice of the median or the mean value to obtain the fetal concentration. Based on differential SNP sites of fetuses and maternal bodies, the fetal concentrations of the male
fetus and the female
fetus are accurately quantified, and then whether the
fetus inherits mutation from the mother or the father under the background of mother mutation or not can be accurately detected in combination with the maternal background provided by the leukocyte sample of the pregnantwoman, so the problem that fetal
genotyping is difficult to perform under the background of maternal mutation is solved.