We present a survey of optically emitting supernova remnants ( SNRs ) in M31 based on H \alpha and [ S ii ] images in the Local Group Survey .
Using these images , we select objects that have [ S ii ] : H \alpha > 0.4 and circular shapes .
We find 76 new SNR candidates .
We also inspect 234 SNR candidates presented in previous studies , finding that only 80 of them are SNR candidates according to our criteria .
Combining them with the new candidates , we produce a master catalog of 156 SNR candidates in M31 .
We classify these SNR candidates according to two criteria : the SNR progenitor type [ Type Ia and core-collapse ( CC ) SNRs ] and the morphological type .
Type Ia and CC SNR candidates make up 23 % and 77 % , respectively , of the total sample .
Most of the CC SNR candidates are concentrated in the spiral arms , while the Type Ia SNR candidates are rather distributed over the entire galaxy , including the inner region .
The CC SNR candidates are brighter in H \alpha and [ S ii ] than the Type Ia SNR candidates .
We derive a cumulative size distribution of the SNR candidates , finding that the distribution of the candidates with 17 < D < 50 pc is fitted well by a power law with the power law index \alpha = 2.53 \pm 0.04 .
This indicates that most of the SNR candidates identified in this study appear to be in the Sedov–Taylor phase .
The [ S ii ] : H \alpha distribution of the SNR candidates is bimodal , with peaks at [ S ii ] : H \alpha \sim 0.4 and \sim 0.9 .
The properties of these SNR candidates vary little with the galactocentric distance .
The H \alpha and [ S ii ] surface brightnesses show a good correlation with the X-ray luminosity of the SNR candidates that are center-bright .
The SNR candidates with X-ray counterparts have higher surface brightnesses in H \alpha and [ S ii ] and smaller sizes than those without such counterparts .