The magnetic torque of Ni-Cl boracite single crystals was measured at 4.2-77°K in a field up to 6700 Oe. From the jump of the angular dependence of the magnetic torque, the spontaneous magnetization of the compd. at 4.2°K was calcd. as 0.72 emu/g. The temp. dependence of the torque is due to the fact that the Ni-Cl boracite is a weak ferromagnet below 9.7°K and a collinear antiferromagnet with sublattice moment in the c direction between 9.7 and 25°K.