Abstract: Polycrystalline samples of La_0.7-xCa_0.28Sr_0.02MnO₃ with different vacancies were prepared by the sol-gel technique,and the effects of the concentration of vacancies in La³⁺- site on the Curie temperature and magnetocaloric properties were investigated. The results show that the Curie temperature of the sample can be adjusted to room temperature effectively,while the magnetic entropy changes of the sample can be increased by La vacancies(x < 0.06). When the La vacancy is doped with x = 0.06,the Curie temperature rises from 227 K to 264 K,approximate to room temperature,and the magnetic entropy change is 3.01 J·kg^-1·K^-1(1T). The magnetic refrigeration capacity is strong when the samples are near room temperature and in low magnetic field.