This study was conducted to investigate the effect of fertilizer composted of dam suspended particle sawdust and sewage sludge to soil properties and seedling growth. The Betula platyphylla var japonica, Zelkova serrata and Chamaecyparis obtusa were used for this study. The soil organic matter, total nitrogen, phosphorous, exchangeable calcium, magnesium, and potassium were increased with fertilizer treatment. Heavy metal concentration in soil was increased with fertilizer treatment, but the level was very low. With fertilizer treatment, growth, photosynthetic capacity, and chlorophyll concentration of seedling were improved.