The magnetic data of La0.7Sr0.3Mn0.98Cu0.02O3 in the ferro-paramagnetic phase transition region has been analyzed using the Modified Arrott plots (MAP), the Kouvel-Fisher and the scaling hypothesis methods. The obtained data is compared to 4 theoretical models: Mean field, 3D Heisenberg, 3D Ising and Tritical mean field. The results suggest that the magnetic interaction in the sample is corresponding to the 3D Ising model. The n value (which relates to the magnetic order) conducted by law is 0.641(8). This value is different from 0.556(5) derived from critical exponents of β and g extracted from fitting values of spontaneous magnetisation and initial susceptibility to Kouvel-Fisher law. A low value of entropy is changed but the relative cooling power is improved.