This paper investigated characteristics of hybrid surface plasmon waveguiding modes in metalclad Si/SiO2 waveguide. Mode characteristics are shown to be highly dependent on structure dimensions and polarization states. By controlling the structure dimensions, a compromise between propagation loss and field confinement can be made for the waveguiding modes. Here, the waveguide had been particularly designed to have very low loss, in which power is mainly confined in the high-index Si-core region to propagate. This waveguide showed excellent bending, isolation and coupling properties that is suitable for high-density integrated photonic circuits.