Abstract:AIM:To observe differences of orthokeratologys functions in controlling or slowing down the development of myopia for teenagers myopia with different diopter. METHODS: After correcting those myopia teenagers with spherical equivalent refraction between -1.00--5.00 D and astigmatism no more than -1.50 D by OK contact lens,169 cases (316 eyes) of myopes were divided into four groups according to the degree of refraction: Ⅰ(dioptre :-1.00--2.00DS), Ⅱ(dioptre : -2.25--3.00DS), Ⅲ(dioptre : -3.25--4.00DS), Ⅳ(dioptre : -4.25--5.00DS) myopic groups. They were followed up at 6, 12, 24 months after wearing glasses. Then results of groups with uncorrected visual acuity over 1.0 and 0.8 were analyzed statistically. RESULTS: Six months after wearing glasses, the ratios of groupⅠ,Ⅱ,Ⅲ and Ⅳ with uncorrected visual acuity over 1.0 were 100%, 96.2%, 93.6% and 88.6% respectively.12 months after wearing glasses, the ratios of groupⅠ,Ⅱ, Ⅲ and Ⅳ with uncorrected visual acuity over 1.0 were 87.3%, 84.8%, 77.2% and 70.9% respectively. Accordingly, the ratios of groupⅠ,Ⅱ,Ⅲ and Ⅳ with uncorrected visual acuity between 0.8 and 1.0 were 12.7%, 15.2%, 22.8% and 29.1% respectively. 24 months after wearing glasses, the ratios of groupⅠ,Ⅱ,Ⅲ and Ⅳ with uncorrected visual acuity over 1.0 were 595%,54.4%,53.2% and 45.6% respectively. Accordingly, the ratios of groupⅠ,Ⅱ,Ⅲ and Ⅳ with uncorrected visual acuity between 0.8 and 1.0 were 152%, 19.0%, 13.9% and 10.1% respectively. CONCLUSION: The results suggest negative correlation between the degree of myopia and the effect of orthokeratology in controlling or slowing down the development of teenagers myopia. Orthokeratology is more effective in group with medium myopia and low myopia than that in group with high myopia. Therefore, its more appropriate for myopia teenagers with early medium myopia and low myopia using orthokeratology. It has advantages such as fast-acting, non-invasive and reversible and can be used in controlling or slowing down the development of teenagers myopia.