We　explored　the　relationship　between　metals　exposure　and　nervous　impairment　in　welders.　The　metals　exposure　of　82　welders　and　51　operators　were　evaluated　for　blood　Pb,　Cd　and　Mn　by　atomic　absorption　spectrometry,　and　the　nervous　system　impairment　was　evaluated　with　the　neurobehavioral　core　test　battery　and　electromyography.　Pb　(geometric　mean:　117.31　mu　g/L;　range:　0.5-327.6　mu　g/L)　and　Cd　(geometric　mean:　3.54　mu　g/L;　range:　0.2-12.5　mu　g/L)　in　welders　were　significantly　higher　than　those　in　operators.　Welders　had　higher　prevalence　of　nervous　system　symptoms　and　worse　standard　scores　of　8　items　such　as　depression-dejection　than　operators.　Significant　difference　of　nervous　performance　in　welders　only　existed　in　different　concentration　groups　of　Pb　and　Mn.　The　performances　of　fatigue-inertia　and　some　others　had　negative　correlations　with　Pb　and　digit　span　with　Mn.　Therefore　the　nervous　system　impairment　in　welders　could　be　attributed　to　occupational　exposure　of　Pb　and　Mn,　but　not　Cd,　concomitantly.