AbstractBackground and objectivesLittle data have been reported on protein molecular weight distribution (MWD) for waxy (amylose‐free) wheat (Triticum aestivum L.) despite their importance in quality. This research aimed to investigate variations of protein MWD parameters and their associations with gluten strength in winter waxy wheat.FindingsWinter waxy wheat genotypes varied significantly (p < 0.001) for most protein MWD parameters including SDS‐extractable polymeric protein (EPP) and unextractable polymeric protein (UPP) fractions, which are major components of gluten proteins. Allelic variation of HMW glutenin subunits had significant influence on variations of EPP and UPP in waxy genotypes. Negative correlations for EPP and positive correlations for UPP were observed with mixograph peak time and gluten index for wheat genotypes. In particular, highly significant (p < 0.001) correlations were observed between mixograph peak time and the proportion of EPP in total protein for waxy genotypes.ConclusionsWinter waxy wheat genotypes showed significant variations for EPP and UPP parameters, which were associated with variation of gluten strength.Significance and noveltyThis research identified variation of protein MWD parameters and their associations with gluten strength. The information should be valuable in segregating winter waxy wheat genotypes that have favorable gluten quality as well as unique waxy starch.