[en] The magnetic properties of UGa₃, UIn₃ and UTl₃ with the AuCu₃-type structure have been investigated over the range of 4.2 - 900⁰K. The magnetic susceptibility of UGa₃ is slightly temperature dependent, whereas those of UTl₃ and UIn₃ indicate the susceptibility maximum at 80 - 90 and 95 - 105⁰K, respectively. The magnetic properties of the investigated compounds are discussed in terms of the crystal field theory, assuming ³H₄ as the ground term of uranium. The termperature dependence of the magnetic susceptibility of UGa₃ indicates the singlet to be the ground level of uranium. The magnetic susceptibility maxima of UIn₃ and UTl₃ can be described in terms of the paramagnetic susceptibility maximum model. The possibility of an antiferromagnetic transition in UIn₃ and UTl₃, however, cannot be excluded. (author)