Context : Spectropolarimetry is a powerful technique for investigating the physical properties of gas and solid materials in cometary comae without mutual contamination , but there have been few spectropolarimetric studies to extract each component . Aims : We attempt to derive the continuum ( i.e. , scattered light from dust coma ) polarization degree of comet 2P/Encke , free from influence of molecular emissions . The target is unique in that it has an orbit dynamically decoupled from Jupiter like main-belt asteroids , while ejecting gas and dust like ordinary comets . Methods : We observed the comet using the Higashi-Hiroshima Optical and Near-Infrared Camera attached to the Cassegrain focus of the 150-cm Kanata telescope on UT 2017 February 21 when the comet was at the solar phase angle of \alpha =75 \aas@@fstack { \circ } 7 . Results : We find that the continuum polarization degree with respect to the scattering plane is P _ { cont,r } =33.8 \pm 2.7 % at the effective wavelength of 0.815 \mu m , which is significantly higher than those of cometary dust in a high- P _ { max } group at similar phase angles . Assuming that an ensemble polarimetric response of 2P/Encke ’ s dust as a function of phase angle is morphologically similar with those of other comets , its maximum polarization degree is estimated to P _ { max } \gtrsim 40 % at \alpha _ { max } \approx 100° . In addition , we obtain the polarization degrees of the C _ { 2 } swan bands ( 0.51–0.56 \mu m ) , the NH _ { 2 } \alpha bands ( 0.62–0.69 \mu m ) and the CN-red system ( 0.78–0.94 \mu m ) in a range of 3–19 % , which depend on the molecular species and rotational quantum numbers of each branch . The polarization vector aligns nearly perpendicularly to the scattering plane with the average of 0 \aas@@fstack { \circ } 4 over a wavelength range of 0.50–0.97 \mu m . Conclusions : From the observational evidence , we conjecture that the large polarization degree of 2P/Encke would be attributable to a dominance of large dust particles around the nucleus , which have remained after frequent perihelion passages near the Sun .