The dead trees, as a soil forming factors and dynamic of forest ecosystems, is regarded an important role in improving fertility. They also effect on biodiversity, regeneration of forest, increasing of forest soil nutrient and soil nutrient cycling. For this study, soil around the dead Populus caspica trees was examined in an area of 382.5 hectare in the Safrabasteh forests of Guilan province. In this study strip transects with 10 meter-wide were used and all of their dead Populus caspica were considered. With respect to the amount of decay, every dead Populus caspica tree was classified into four groups called new dead tree, decay beginning, advanced decay and full decay. Beside each dead tree, three soil samples were collected from the depth of 0-20 cm and were sent to the laboratory for analyzing. In this study, the chemical characteristics of soil included Organic carbon, Nitrogen, Phosphorus, Potassium, EC, C/N and pH were analyzed. The results obtained from this study indicated that there is significant difference in some soil chemical properties at the confidence level of %95 between the different degrees of decay. The highest amounts of soil chemical properties were under advanced and full decay. Based on the results, it can be declared that soil chemical characteristics in different degrees and distances differ can be changed.