Taking care of mentally retarded children creates many problems for mothers. The problems lead to mother's care burden and forgetfulness of self-care by her. Due to the effective role of spiritual confrontations in meeting the psychological needs of the mothers with mentally retarded children, this study aims to determine the effect of spiritual self-care on care burden of the mothers with mentally retarded children who are supported by Elahi rehabilitation center in Quchan. This is a semi-experimental study in which 60 mothers with mentally retarded children are considered by the before-and-after test. Sample population of the study are the total available number of these mothers. The qualifications the mothers need include being Muslim, having at least primary school literacy, being the real parent of the child, etc; and the exclusion qualifications include being a member of religious minority, illiteracy, being unreal parent of the child, having depression, etc. Sample population are divided randomly to the intervention group and the control group. Data collection tools include a personal information researcher-made questionnaire with 14 questions based on research purposes. The questions are about age, marital status, education level, income, job, number of children, place of residence and gender of children. To determine the questionnaire validity, the corrective comments and suggestions of 10 professors of Zabol Nursing and Midwifery faculty were used. Caregiver burden questionnaire (Novak &Guest, 1389)with 24 items is also used to measure objective and subjective caregiver burden. The questionnaires are completed before, immediately after and two weeks later of the spiritual self-care training. For data analysis, SPSS20 software is used.