The aim of this study is to examine the sensitivity and characteristics of electromyography abnormalities detected by using various paramenters in patients with lumbosacral radiculopathies. EMG is widely used for disgnosing and localizing the level of radiculopathy. The results of the study were as follow : 1. In electromyography, L5 radiculopathy usa 95 cases(51.690). S1 radiculopathy was $45m(24.5\%)$ L4 radiculopathy was 18cases $(9.8\%)$, and L2, 3 radiculopathy was 8cases$(4.3\%)$. Remains 18cases$(9.8\%)$ had no definite radiculopathy. 2. Peroneal and tibial motor nerve conduction velocity studies were not significant as compared to the side to side. 3. Latency of H-reflex in L5 radiculopathy was $30.55pm2.47$ in affected side, $29.47pm2.29$ in unaffected side, in S1 radiculopathy was $33.00pm2.03$ in affected side, R30.18pm2.21$ in unaffected side. It was statistically significant(p<0.01). H-reflex mean difference of S1 radiculopathy group was significantly prolonged as compared to the L5 and S1 radiculopathies(p<0.001). 4. In L2, 3 radiculopathy, abnormal spontaneous activities and motor unit action potentials were showed high sensitivity in upper lumber paraspinal, hip adductors, quadriceps and iliopsoas muscles. 5. In L4 radiculopathy, lower lumbar paraspinal, tibialis anterior, quadriceps muscles were showed high sensitivity. 6. In L5 radiculopathy, lower lumbar paraspinal, extensor hallucis longus, extensor digitorum longus, peroneus longus, extensor digitorum brevis, gluteus maximus, tensor fasciae latae muscles were showed high sensitivity. 7. In S1 radiculopathy, lower lumbar paraspinal, gluteus maximus, peroneus longus, soleus, abductor hallucis, hamstrings, extensor digitorum brevis, extensor hallucis lognus, gastrocnemius muscles were showed high sensitivity.