Objective: To identify associations between anthropometric indicators (height, weight and body mass index (BMI)) and both refraction and ocular biometrics in Chinese schoolchildren in Tianjin, China., Design: Cross-sectional study., Participants: A total of 482 (86.07%) students (6-15 years old) with no history of ocular or systemic pathologies were enrolled in this study., Methodology: Height and weight were measured using standardised protocols. Ocular biometrics (axial length (AL), vitreous chamber depth (VCD) and corneal curvature (CC)) were measured by a low-coherence optical reflectometry device. Cycloplegic refraction was measured using autorefraction. The AL/CC ratio and spherical equivalent refraction (SER) were calculated. Myopia was defined as SER ≤-0.50 dioptres (D). Multiple linear regression analysis was performed to explore the associations between anthropometric indicators (height, weight and BMI) and both refraction and ocular biometrics., Results: The overall prevalence of myopia was 71.16%. Overall, only height was associated with ALs, VCDs, AL/CC ratios and refractions after controlling for age, gender, parental myopia, family income, reading and writing distance and time spent outdoors. Furthermore, age-specific results demonstrated that height and weight were independently associated with refraction in participants aged 6-8 years and 9-11 years participants. Higher heights in schoolchildren were associated with longer ALs (regression coefficient b =+0.25 for each 10 cm difference in height, p<0.01), deeper VCDs ( b =+0.23, p<0.01), higher AL/CC ratios ( b =+0.04, p<0.01) and more negative refractions ( b =-0.48, p<0.01). Heavier weights were also associated with longer ALs (+0.29 mm, p<0.01), deeper VCDs (+0.29 mm, p<0.01), higher AL/CC ratios (+0.04, p<0.01) and more negative refractions (-0.48 D, p<0.01)., Conclusions: Height and weight remained independently related to refraction and various ocular biometrics during the early adolescent growth period after adequately controlling for covariates, which could support the idea that a shared mechanism may regulate the coordinated growth of body and eye size in children., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2019. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)