: Nowadays, Enviromental Pollution is an important problem in different countries. Increase of population, expantion of cities, industrial practices and human interface in the nature, caused the pollution of air, water and soil.In recent years phytoremediation proposed as a cost effective technology to remediate soil polluted to heavy metals. Approximately 400 hyperaccumulator species have been identified in the world. However,most hyperaccumulators are as a low biomass producing and slow growing plants and not suitable for commercial application. Plants are known that have high biomass and rapid growth but they have two limitation:low bioavaibility in soil and low heavy metal translocation from roots to shoots. Chemical amendments can enhance phytoremediation by increasing HMs bioavailability in soil and translocation of HMs from the roots to shoots. The objective of this research is to study affecting factors on enhancing the phytoremediation efficiency of soil polluted to lead and cadmium. And heavy metal accumulation in roots and shoot of high biomass producing and rapid growing plants and soil ammendment effect at different initial pollution are studied. The experiment was conducted in a factorial design with 3 replication. Soil used in this study was artifically contaminated with heavy metals in 3 levels (400, 700 and 1000 mg lead per kilogram of dry soil and 5,10 and 20 mg cadmium per kilogram of dry soil). The experimental plants were maize and sunflower. Planting conducted in research greenhouse of Isfahan University of technology, Isfahan, Iran during ten weeks. Soil amendments including 2.5,5 and 10 mmol citric acid and EDTA per kilogram of dry soil added to soil 1 week before plant harvesting. Data were analyzed by using SAS and software.The results releaved that root and shoot dry weight decreases with increasing initial pollution, and application EDTA and citric acid decrease root and shoot dry weight. The results showed that lead and cadmium contcentration accumulated in sunflower is more than maize. Application EDTA and citric acid is very effect on enhancing lead and cadmium contcentration in root and shoot, but addition of EDTA to soil on enhancing root and shoot cadmium contcentration is less than lead. Applying Citric acid can not significantly increase lead and cadmium contcentration and only high level citric acid can increase lead and cadmium contcentrationin the root and shoot.
