  We universally search for evidence of kinematic and spatial correlation of
supernova remnant (SNR) and molecular cloud (MC) associations for nearly all
SNRs in the coverage of the MWISP CO survey, i.e. 149 SNRs, 170 SNR candidates,
and 18 pure pulsar wind nebulae (PWNe) in 1 deg < l < 230 deg and -5.5 deg < b
< 5.5 deg. Based on high-quality and unbiased 12CO/13CO/C18O (J = 1--0) survey
data, we apply automatic algorithms to identify broad lines and spatial
correlations for molecular gas in each SNR region. The 91% of SNR-MC
associations detected previously are identified in this paper by CO line
emission. Overall, there could be as high as 80% of SNRs associated with MCs.
The proportion of SNRs associated with MCs is high within the Galactic
longitude less than ~50 deg. Kinematic distances of all SNRs that are
associated with MCs are estimated based on systemic velocities of associated
MCs. The radius of SNRs associated with MCs follows a lognormal distribution,
which peaks at ~8.1 pc. The progenitor initial mass of these SNRs follows a
power-law distribution with an index of ~-2.3 that is consistent with the
Salpeter index of -2.35. We find that SNR-MC associations are mainly
distributed in a thin disk along the Galactic plane, while a small amount
distributed in a thick disk. With the height of these SNRs from the Galactic
plane below ~45 pc, the distribution of the average radius relative to the
height of them is roughly flat, and the average radius increases with the
height when above ~45 pc.
