The reduction of pellets under load was done based on the simulating COREX reducing conditions. The influence of temperature, reduction gas composition and load on sticking was studied. Meanwhile, the microstructure and composition of sticking were analyzed by SEM-EDS and XRD. The results showed that the main composition of sticking was metallic iron and the pellets sticking belong to the solid phase bonding in the way of metallic irons diffusion and mutual infiltration. The sticking and metallization degree of pellets increases as the reduction temperature changes form 750℃ to 950℃. When the content of H₂ increased, the sticking and metallization degree of pellets was improved. Load was another factor of worsening the sticking.