Background: Calculating the peak growth indicator of chronological age on the development of children may not be as accurate as the biological age assessed based on the degree of cervical vertebra maturation. Objectives: To determine the correlation between chronological age and cervical vertebral bone age by qualitative method (Baccetti, 2005), quantitative methods (Mito, 2002) and (Thuy Trang, 2015), thereby finding out the method is suitable for application on Vietnamese. Materials and Methods: A simple random sample of 90 pupils aged 6 - 8 years old at Phu Mau Primary School, Thua Thien Hue province was taken the lateral cephalometric films and evaluated the degree of cervical vertebra maturation by three above methods. Results: (1) according to cervical vertebral bone age, the female children tend to mature earlier than male by 0.04 - 0.23 years, an average of 0.14 years (p < 0.05); (2) the correlation coefficient between cervical vertebral bone age and chronological age with the Thuy Trang method (r = 0.33, p < 0.001) is higher than the relationship in the Mito method (r = 0.24, p < 0.05) and with the Baccetti method (r = 0.10, p > 0.05). Conclusions: Using age of cervical vertebrae can objectively assess maturity related to chronological age on the lateral cephalometric. It is necessary to combine qualitative and quantitative methods to determine cervical vertebral bone maturity on cephalometric films. Key words: chronological age, cervical vertebral bone age.