Аннотация:The study of RCo5-based compounds presents a keen interest due to the existence of two magnetic sublattices in them. This work is dedicate to the investigation of magnetic properties of RCo5-xGax and determination of the strength of intrasublattice and intersublattice exchange interactions. It was found that the paramagnetic susceptibility of GdCo5-xGax follows the Neel law. For these compounds the molecular field coefficients were calculated. This allowed to determine the contributions of Gd and Co sublattices to the magnetization.