To provide the woody needs and uses of Guilan wood and paper company, a plan of reforestation in Pilambara clearly harvested forests have operated in 1448 hectares of Pilambara in 1974. Pilambara is a low forest area located in Northwest of Caspian forests with 35 foret compartements and 18-S- meters above sea level and average slope of 0-5 percent and is operated by Shafarood forest company. After harvesting of endemic species like Quercus castanaefolia, Carpinus betulus, Parrotia persica, Ulmus grandifolia,Fraxinus excetsior ,Salix sp. and Diospyrus lotus from the natural forest site and severe degradation of natural forests, reforestation of exotic fast growing species like Pinus taeda, Pinus radiate, Pinus eliuti and Cryptomaerya japonica have come into consideration to benefit from their softwood. Now after 30 years of plantation ,we have arranged a research to identify the effects of this reforestation on soil characteristics and vegetation cover of two forest compartments(9 and 24) of Pilambara forestry district. The study of trees health have shown that most trees of reforested stands (8 1%) are polluted by Limanteria dispar and bark beatle so hard causing decrease of wood quality and decrease of all existing trees including also neighboring natural stands with endemic hardwoods. ALso the laboratory experiments showed that the pH of soils is decreased about 0.5-0.6 and now is going towards acidsoil. Also with the comparison of coverage of grass on forest grounds in 2002 with coverage in 1974 declared decrease of approximately 30 percent in grass covcragc. At last some nutrients like Calcium and phosphor have been decreased too due to decrease of pH and soilacidity.