At present time,due to depletion of petroleum production lands,the problem of land reclamation becomes pressing.One of the main conditions of natural ecosystem recovery is the restoration of soil cover.In the work presented,thecomposition and peculiarities of peat soils exchangeable cations and its influence on vegetation state on petroleum production lands of Central Ob region were investigated.The whole quantity of exchangeable cations in soils of every plot studied is in accordance with cation exchange capacity level of natural peat soils for this region.The most of soils are characterized by anomalous quantity of exchangeable Ca,Mg and Na and extremely high exchangeable acidity.The quantity of exchangeable K is also higher than in natural soils.High level of Ca and Mg in soil exchange complex (SEC) is related to insertion of anti-acid agents during reclamation process and to entrance of those elements with dust deposition.Great amount of Na in soils is connected with salted formation water income because of raw petroleum and water pipeline breaks.Up to 25% of incoming Na passes to SEC,residual Na stays in water soluble compounds.In the absence of petroleum and salt pollution,in case of low exchangeable acidity level and high contents of Ca and Mg,land overgrown was found.Vegetation kind in this case may differ from natural peatbog.Vegetation depression against a background of high Ca and Mg content and low acidity level is mainly related to oil and salt pollution.For the natural peatbog vegetation renewal the following soil conditions are required:relatively high acidity level,related mainly to H+,non-salted draining water,low contents of exchangeable cations except H+,suitable water and air regimes.