The development of forest ecosystems compromises three stages including initial, optimal and decay.In all these stages, the changes in canopy volume and amount of light reaching lead to changes in soil physiochemical and biological properties. Enzymes activities as biochemical properties are of the most important indicators to determine the soil quality. This research aims at assessing the soil condition is in different development stages. For this purpose, phosphatase enzymes activities and some physical properties of soil in different development stages of Fagus orientalis Lipsky forests in Rezvanshahr area were determined. Soil samples were randomly taken from 0-10 and 10-20 cm depths. Activity of phosphatase enzymes was measured by spectrophotometry method. Some physical properties of soil such as bulk density, porosity were determined by standards methods. The results indicated acid and alkaline phosphatase enzymes activities were significantly different in terms of silt percent (p≤0.01), bulk density amount, and first depth (p≤0.05) in three development stages. The values of all measured properties were higher in decay stage except for bulk density amount in 0-10 cm depth than two other stages. In addition, the activity of acid phosphatase (depth 0-10) and alkaline phosphatase (depth 10-20) was positively correlated with available phosphorus in decay stage. It is concluded that the decay stage provides better conditions to the soil micro-organisms and phosphatase activity.