Abstract: In this research we have studied the peripheral blood neutrophils phagocytosis and serum opsonic capacity by luminal excited chemiluminescence method. in 73 cases, who, evaluated in this research, none of them received any therapeutic drugs. All of cases, consists of 34 normal subject (female=l9, male=l5) and 18 patient control (included RA= 5, JRA=1, Polymyositis = 1, Behcet disease = 2, AS =3, Vascuiitis = 3 and scleroderma = 3) and 21 patients with SLE, which divided into two subgroups (mild = 13, Moderate = 4). Results: We faun that PMN - Chemiluminescence and serum opsonic capacity in patients suffering SLE decreased and show a significant differences with patient controls and normal controls (P<0.050). In this level we also didn't obtain any differences in two subgroup of SLE patients. Furthermore, in comparison of patients with RA disease, SLE patient and normal controls, PMN-CL in RA patients increased and show a significant differences (P<0.050). On the other hand, PMN-CL and SOC on total samples has shown significant linear relation (r=0.75, P=0000), but in individual analysis of groups, we have just this relation in SLE patients (r=0.58, P=0.005).