Ghanem A Shehoob.¹Una M EL Shinnawi².Mohammad M anees.³Azza EL-baiomy ^{4 1-BDS, Faculty of Dentistry, TripoliUniversity, Libya 2-Professor of Oral  Medicine& Periodontology, Faculty of Dentistry, Mansoura University. 3-Assistant of Oral  Medicine& Periodontology, Faculty of Dentistry, Mansoura University. 4-Professor  of clinical pathology,Faculty, of Medicine, Mansoura University.} Abstract: objective: The aim of this study to evaluate the CD40L with CVD adjunctive treatment to scaling and root planning (SRP) of patients with moderate chronic periodontitis. Subjects and Methods: Forty five subjects were included in the study. fifteen  subjects  as chronic peiodontitis with CVD and fifteen subjects as CVD Patients and fifteen  subjects  as chronic peiodontitisas study groups. Full-mouth clinical periodontal  parameters, including periodontal probing depth, plaque index, gingival index and gingival bleeding index) were recorded at baseline in all groups and after treatment  in study groups. Serum sample was collected at baseline and four weeks  after therapy for  groups I&III and at baseline for the  group II. Result: The results of the present study, showed a significant reduction in all clinical parameters (GI, PI, PPD, GBI and  CAL)  after treatment in group I&III. The CD40L were highly significantly reduced after treatmentin groups I&III. Were versus of CD40L in groups high levels in CVD with chronic periodontitis versus groups II&III.  At base line and after treatment both sides of study group was high significant   in clinical parameter and levels CD40L. Conclusions: CD40L is elevated in chronic periodontitis patients as well as in CVD patients. CD40L level in serum has been found to decrease after phase 1 periodontal therapy. Key word: CD40L, CVD and chronic periodontitis