Abstract: Provided in the present disclosure are a method for determining fetal nucleic acid concentration and a fetal genotyping method. According to the embodiments of the present disclosure, the method for determining cell-free fetal nucleic acid concentration includes: (1) acquiring sequencing data of a first nucleic acid sample of a pregnant woman and a reference genome sequence, the first nucleic acid sample of the pregnant woman containing cell-free fetal nucleic acids, and the sequencing data being composed of a plurality of sequencing reads; (2) selecting a predetermined region on the reference genome sequence and determining, based on the sequencing data of the first nucleic acid sample of the pregnant woman, mutation information in the predetermined region; and (3) determining the concentration of cell-free fetal nucleic acids corresponding to the predetermined region based on the mutation information in the predetermined region.