Objective To analyze mitochondrial DNA (mtDNA) in the displacement loop (D-Loop)region in pathological myopia subjects and controls.Methods Experimental study.Genomic DNA was extracted from 127 pathological myopia subjects and 104 controls.PCR-amplification of the D-Loop region and bidirectional sequencing was done according to the revised Cambridge reference sequence (rCRS) and all variants were analyzed.Data were analyzed using independent samples t test and frequency of variants using Chi-square test and Bonferroni correction.Results One hundred and sixty-eight variants were found in 127 pathological myopia subjects.Of these,3 were new variants and 53 variants were only found in the pathological myopia subjects and not in the controls.There were 1270 variants in 127 pathological myopia subjects,with an average of 10 variants in each subject.None of the variants was statistically associated with pathological myopia.The frequency of mtDNA T152C in pathological myopia subjects and controls was 19.7％(25/127) and 31.7％(33/104),respectively.Chi-square tests showed there were significant differences between the pathological myopia and control groups (x2=4.412,P=0.036),but Bonferroni correction did not show significant differences.Conclusion The displacement loop region of mitochondrial DNA in pathological myopia is a hot spot for mutations.Additional studies should be done on mitochondrial DNA D-Loop variants and pathological myopia.