Abstarct: In order to investigate the effect of some endophytic fungi and foliar spraying of iron nanoparticles on phytoremediation of purslane (Portulaca oleracea L.) under different levels of cadmium (Cd), a research was carried out in Sari Agricultural Sciences and Natural Resources University during 2016-2019. This research was conducted in three stages including two preliminary and a supplementary phases. The first preliminary step was conducted in a factorial experiment in a completely randomized design with three replications in order to select the best treatment levels for both iron nanoparticles and cadmium. Iron nanoparticles consisted of five levels (0, 0.25, 0.5, 0.75 and 1 g/l) and cadmium at six levels (0, 25, 50, 75, 100 and 125 mg/kg soil) from the source of cadmium chloride. At this stage, the results indicate a decrease in all growth and physiological parameters of purslane by increasing the Cd levels in soil.The maximum reduction in morphological and growth parameters was recorded for plant height, leaf area (about 50 and 45 percent) and shoot fresh weight (more than three times lower), respectively. The most positive effect of foliar spraying of iron nanoparticles in morphological traits, at a concentration of 0.25 g/l was observed in purslane plant height and leaf area. Also, at the same concentration of nanoparticles, the relative water content (RWC) increased by 14%. Catalase activity increased when 0.3 g/l of iron nanoparticles was applied. The most changes in the measured parameters in response to the Cd in the soil occurred at the levels of 0 to 75. Therefore, according to the results of this stage, levels of 0, 25, 50 and 75 g/kg of Cd in the soil were selected for the second preliminary stage and supplementary experiment. To more accurate and better evaluate the effectiveness of nanoparticles, concentrations of 0.15 and 0.3 g/l were selected for supplementary experiments. The second preliminary stage aimed to investigate the effect of 13 symbiotic fungal isolates of roots in Sari areas of Mazandaran and Shahroud areas in Semnan province along with Piriformospora indica and Trichoderma longibrachiatum (UTFC 10060) as control fungi. Tolerance and phytoremediation of purslane were investigated using a factorial experiment baxsed on a completely randomized design with three replications. Cluster analysis classified fungal isolates into four classes according to their effects on purslane. Results indicated Chaetomium subaffine (SF3) and T. atroviride (SN1) classified in the best group in terms of their positive effects on the measured traits. Results also confirmed their symbiosis with purslane roots. In addition, T. longibrachiatum (UTFC 10060) also showed a better performance than P. indica and, therefore, was selected for supplementary experiment. In the supplementary experiment, the effect of foliar spraying of iron nanoparticles (0, 0.15 and 0.3 g / l) and C. subaffine (SF3) and T. atroviride (SN1) selected endophytic fungi and T. longibrachiatum (UTFC 10060) as control fungi were investigated in term of the purslane tolerance and phytoremediation ability against different Cd concentrations. A factorial experiment baxsed on a completely randomized design with three replications was applied. The results of the supplementary test showed that increasing the Cd toxicity of soil reduced all growth and morphological traits in purslane. Cd increased hydrogen peroxide (H2O2), electrolyte leakage (EL) and membrane lipid peroxidation .Cd, also, reduced the RWC, chlorophyll content and thus reduced photosynthesis and growth. Symbiosis with C. subaffine (SF3), T. atroviride (SN1) and T. longibrachiatum (UTFC10060) fungi markedly improved purslane growth, morphological and physiological parameters. In inoculated plants, plant height, leaf number and area, stem diameter as well as leaves fresh and dry weights increased as compared to the uninoculated plants. Also, these fungi ameliorated the negative effects of Cd toxicity in the plant not only by reducing the EL, H2O2 and malondialdehyde (MDA) but also by increasing the RWC and proline. As a result, the activity of antioxidant enzymes decreased in inoculated plants. Application of 0.15 and 0.3 g/l of iron nanoparticles also showed a positive effect on the growth parameters of purslane by reducing oxidative stress and increasing the activity of antioxidant enzymes, proline content and RWC and ultimately improved photosynthetic conditions. With increasing Cd concentration in the soil, its amount increased in the roots and shoots of purslane, also increased the biological characteristics of this plant. On the other hand, fungal inoculation also increased the phytoremediation ability of purslane. Inoculated plants could uptake more absorbable Cd from the soil than the control. Also, the amount of Cd increased both in the root and its transfer to the shoot, which eventually led to an increase in biological factors. Application of iron nanoparticles also improved Cd uptake and thus increased biological indicators by improving the nutritional and growth conditions of the plant under Cd stress. In general, in this experiment, fungal isolates of C. subaffine (SF3) and T. atroviride (SN1), which were isolated for the first time in Iran from froriepia (Froriepia subpinnata) and watercress (Nasturtium officinale) as endophytic and root symbiosis fungi can be introduced that in purslane improved growth and phytoremediation process and reduced oxidative stress under Cd stress. Also, results of iron nanoparticles indicated a positive effect on the growth characgristics of purslane under Cd toxicity.