[en] The magnetisation of Dysub(x)Cesub(1-x)Ru₂ (x = 0 to 1) has been measured at temperatures ranging from 1.5 to 300 K. In the alloys with concentration in the range of 0.15 =< x < 0.24, two critical temperatures, i.e. a superconducting transition temperature and a paramagnetic Curie temperature have been observed at low temperatures, but no ferromagnetic hysteresis has been observed at temperatures down to 1.5 K. It has been found that the observed total magnetisation can be expressed by the sum of the superconducting magnetisation and the normal state (nonsuperconducting) magnetisation and that this expression holds whether the field is smaller than Hsub(c1) or not. The magnitude of the initial slope of the magnetisation against magnetic field curve decreases with increasing x and is smaller than that of the perfect diamagnet. A domain structure model, composed of superconducting domains and nonsuperconducting domain boundaries, is proposed to explain the present experimental results. (author)