The frequency of lactase persistence varies widely in human populations. Study showed that the T allele of a C/T transition 13910bp upstream from exon 1 of lactase gene (LCT) was completely associated with lactase persistence in a Finnish population. To evaluate if the frequency of -13910T allele was in concordance with the lactase persistence in northern Chinese populations, in this study, we used Polymerase Chain Reaction-Restriction Fragment Length Polymorphism (PCR-RFLP) to detect the lactase -13910T allelic frequency in 5 northern Chinese populations for the first time. Results showed that the T allele frequency was low in these populations and that it did not match the lactase persistence phenotype in these populations. Therefore the -13910T allelic frequency can not serve as a predictor of the lactase persistence in these populations and this suggests the existence of other possible mechanisms of lactose tolerance in Chinese populations.