Objectives: This project was aimed at investigating the effect of social support on immune parameters in healthy individuals accord-ing to the main effect model.

Method: Following the completing of a social support Questionnaire by 200 male subjects, 16 individuals with high social support and 16 individuals with low social support were selected. The subjects were matched by age, sex, nutrition, sleep, exercise, physical and mental health, and stress. In the early hours of the day of assessment, 7 ml blood samples were gathered from the subjects in the supine position. Blood samples were analyzed in the laboratory to determine the amount of lymphocytic response to PHA, as well as the percents of CD3+,CD4+,CD8+, and CD56+ and ratio of CD3+ to CD8+. The data were analysed through t-test.

Results: The findings showed that subjects with high social support had higher Lymphocyte Transformation Test (LTT) levels and CD56+ percentages than those with low social support.

Conclusion: People with higher social support possess more com-petent immunity and the results are in favor of confirming the main effect model.