[Purpose] This study was conducted to compare and analyze influence of craniocervical flexion and suboccipitalis relaxation in cervicogenic headache patients of their cervical muscular fatigue, tone, and headache intensity. [Subjects and Methods] 30 patients with cervicogenic headache were selected and 10 subjects per group were randomly assigned to control group, craniocervical flexion exercise group, and suboccipitalis relaxation group. Intervention for each group was provided 5 times a week for 4 weeks. Muscular tone test and muscular fatigue test were conducted on both sides of upper trapezius and sternocleidomastoideus and visual analogue sclae on the headache intensity was conducted before the intervention, after 2 weeks, and after 4 weeks. [Results] Difference from intervention was significant in muscular fatigue of upper trapezius and sternocleidomastoideus, muscular tone of sternocleidomastoideus, and headache intensity. Correlation between intervention duration and the groups showed significant difference in muscular fatigue, muscular tone, and headache intensity except left upper trapezius muscle. [Conclusion] From this study, 4 week application of crainiocervical flexion exercise and suboccipitalis relaxation on cervicogenic headache patients was found to be effective in decrease of muscular fatigue of upper trapezius and sternocleidomastoideus, muscular tone of sternocleidomastoideus, and headache intensity.