main goal of this investigation was the formation of the reference values of ventilatory variables for group of adolescents of both sexes at the age between 15 and 19 years, what was done for the first time for the region of Vojvodina. These values are important in evaluation of respiratory data obtained from patients in the everyday routine examinations. The investigation was carried out on 1 151 healthy school children – nonsmokers having the same ethnic origin from the region of Vojvodina. There were 567 males and 584 female participants. Vitalograph ® dry spirometer (Vitalograph ® Ltd, Moreton House, Buckingham, England) was used in these examinations. The whole procedure was explained and demonstrated to the participants and best results of their consecutive attempts were taken for further sta tistical analysis, i.e., for calculations of the mean, SD, SEM, coefficient of variation and linear regression. All tests were performed in the morning hours between 8–12 a.m. The results obtained served for calculating the reference values of forced vital capacity (FVC), volume expired in first second of FVC (FEV1.0) and forced midexpiratory flow (FMF). A positive correlation between the respiratory variables and the body height values was found in all groups of participants. The equations of the linear regression related to the ventilatory variables and the height (in 5 cm intervals) were formed separately for both genders. Analysis of the data shows significant differences of the values for all respiratory variables between males and females, which increased with the increasing height of the person. The values for the male group were always higher. In taller volunteers the difference between the sexes becomes even statistically significant, what points that it is necessary to calculate the equations for each gender sep arately.

        Key words: adolescents, reference values, mathematical models, FVC, FEV1.O. FMF