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The effects of initial spacing layout on some allometric characteristics of 12-year-old Quercus castaneifolia trees grown in Central Mazandaran, north of Iran were examined. Trees were planted in 5 different layouts (1×1, 1.5×1.5, 2×2.5, 2×3 and 4×4 m). Tree height, diameter at breast height, natural pruning height and the survival of trees were recorded in each sample plot. Tree basal area and H/D ratio and standing volume were calculated for all trees. The results of statistical analysis showed that increasing in spacing level from 1×1 to 4×4 significantly increased the average diameter at breast height from 6.93 to 12.42 cm and survival from 53% to 85%. The average tree basal area per ha decreased from 19.98 m^2 ha^-1 to 6.43 m^2 ha^-1 and H/D ratio from 151 to 77 when the distance between trees increased from 1 × 1 to 4 × 4 m. but spacing regime had no significant effect on tree height and natural pruning height. It can be concluded that on the basis of standing volume, H/D ratio and survival rate, the best plantation spacing in this research station was 2 m × 3 m. Statistically, about 95% of the changes in sediment yield was due to the effect of increased dry land farming area in the basin (R^2= 0.95, α < 0.05).