Abstract: In order to investigation of afforestation operation, Pinus brutia Ten. (Red pine) in Ghapan region (Golestan province-North of Iran) was selected. Planted stands were classified to three altitude classes of 200-400, 400-600 and 600-800 m. Mentioned afforestation was located in northern aspect with 16 years old, plantation distance of 2x3 m and with 232 ha-1 areas. In this study diameter at breast height, height, form factor, diameter increment and stand volume parameters were calculated. Statistical analysis was done by SPSS and EXELL software's in order to study the distribution of trees in diameter and height classes. Results of this research showed that diameter mean of trees were 12.40, 12.96 and 14.42 cm at the first, second and third classes also, height mean were 7.06, 7.22 and 8.02 m at the first, second and third classes, respectively. This study showed distribution of diameter mean at breast height and height was similar to normal distribution and also, volume of Pinus brutia Ten. were estimated 41, 47.41 and 95.80 silve ha-1 at the first, second and third classes. Mean annual increment of diameter were 0.91, 0.98 and 1.15 cm at the first to third classes, respectively. Totally, Quantitative characteristics showed regular changes with respect to different altitudes and 600-800 m altitude class had best results for quantitative characteristics.