The　surface　wave　modes　on　right-handed　helically　grooved　metal　wire　waveguide　and　left-handed　one　were　studied　and　compared.　It　was　found　that　for　the　helically　grooved　waveguide,　the　normal　degenerate　HE1　SSPP　(spoof　surface　plasmon　polaritons)　mode　decompose　into　two　opposite　circularly　polarized　modes,　i.e.,　HE　-　1　and　HE　+　1　SSPP　modes　due　to　the　chirality　of　helical　grooves.　The　divarication　between　dispersion　curves　of　HE　+　1　and　HE　-　1　modes　can　generate　a　circular-polarization　band.　Moreover,　a　positive　or　negative　superchiral　field　can　be　obtained　for　the　right-handed　grooved　and　left-handed　grooved　wire　respectively　due　to　the　near　field　enhancement　effect.