Abstract: This study was designed to analyse the geographic differences of Chinese youths' Rohrer'sIndex curves by using multivariate analysing method. The means of height, weight and Rohrer'sIndex of those aged 7, 13(11 for gir1s), 18 and 22 years were used as parameters. Firstly, by using factor analysis, two factors were extracted, both for boys and girls, from these parameters.Then by using the factor scores as new variables and by using the Q mode cluster analysis, both boys' and girls' groups were classified into several clusters. Comparisons between these clusters showed significant urban-rural differences, north-south differences as well as developed-'underdevcloped differences, not only on youths' body size, but also on their body shape. Rohrer's Index curves were set up and smoothed by the polynomial fitting equations for each of these clusters, and the use of these curves in setting up the norms in screening out the individuals with abnormal nutrition and health status were discussed.

Key words: Chinese youth; Rohrer's Index; Geographic difference