Phytoremediation i a technique that removes pollutant from soil by plant. Sewage sludge (SS) is a source of organic matter, as well as macro- and micro-nutrients for plants. However, high concentration of heavy metals and pathogens in SS may causes contamination of agricultural soils. Converting SS to biochar (BC) by pyrolithic process could be an acceptable approach for using SS. Symbiosis microorganisms such as Piriformospora indica fungi with plant root have positive effect on uptake of metals by plant. To investigate the effects of P.indica , SS and the BC of SS on arsenic uptake by sunflower, we conducted a greenhouse experiment with sand and soil-beds. A randomized complete block design in a factorial experiment with three replications used to analysis the observed data. Treatments included control (plants without any P.indica , SS and BC), P.indica (two levels; inoculated and non-inoculated), SS (two levels, 20 and 10 ton ha -1 ), BC (two levels; 10 and 20 ton ha -1 ), two levels of BC- P.indica (10 and 20 ton ha -1 ) and two levels of SS- P.indica (10 and 20 ton ha -1 ). The soil is naturally contaminated (As concentration of 215 mg/kg) with As which was collected from Kurdistan province. Arsenic with three levels (0, 15 and 30 mg kg -1 ) applied only to the pots filled with sand. Our results showed that inoculation by P.indica and organic fertilizer increased sunflower yield significantly. Sunflower yield significantly decreased with addition of As to sand beds. All the sunflower plants died at the 30 ppm As concentration added to the sand bed pots. Because of decomposition of SS and organic acids production, soil pH decreased. Also, SS with adding organic carbon (OC) and increasing plant production, increased %OC in soil. Inoculation by P.indica also increased the %OC in the soil. SS increased soil microbial respiration and water repellency. Microbial respiration and soil water repellency showed a positive correlation with soil organic carbon, as the BC decreased As concentration in plant but SS increased this parameter. As-uptake (concentration×yield) was higher in BC treatment despite the lower concentration of As in sunflower plants. Inoculation by P.indica increased concentration and uptake of As in plant. The SS and BC increase and decrease the uptake index, respectively. Also, inoculation by P. indica increased uptake index of As in the soil bed. Keywords : Plant uptake, Arsenic, Sewage sludge, Biochar, Sunflower.