  The supernova remnant (SNR) IC 443 is one of the best-studied Galactic SNRs
at many wavelengths. It is interacting with a very complex environment,
including the SNR G189.6+3.3 and HII regions. In this paper, we observed IC 443
and G189.6+3.3 using 1.5- and 1-m telescopes to better understand the nature of
these SNRs in the optical band. We perform H_alpha images showing both
filamentary and diffuse structures, and long-slit spectra from many locations
with Balmer and forbidden lines detected for IC 443 and G189.6+3.3. The [SII]/
H_alpha ratios confirm the SNR nature of G189.6+3.3. The ranges of our
estimated electron density and pre-shock cloud density clearly indicate the
complex structure surrounding IC 443 and G189.6+3.3. We also investigated the
archival HI data and newly found some shell-like distributions of HI that are
possibly associated with G189.6+3.3.
