In order to predict the seed quality of oil flax through seed morphology-related traits，eight seedmorphology characteristics and seven seed-quality traits were detected in 238 oil flax germplasm accessions. The results showed higher variation coefficient on yellowness，seed surface area，1000-seed weight and lignan content，as well as lower variation coefficient on the seed circumference，oil content，palmitic acid and linolenic acid content. The highest average values on traits of seed lightness，linoleic acid and lignan contents were observed in improved cultivars，and the highest average values on traits of seed redness and yellowness，palmitic acid，stearic acid and oleic acid contents were detected in landrace cultivars. The exotic cultivars showed the highest average values on seed length，width，circumference，surface area，1000-seed weight，oil content and linolenic acid content. Regarding to the seeds of accessions with different color，the lightness，yellowness，palmitic acid，stearic acid，linolenic acid，lignan content and oil content of the yellow seeds were higher than those of the brown seeds. The seed length，width，circumference and surface area were positively correlated with and contributed to the thousand-seed weight. The accessions with bigger seeds and lower redness was briefly associated with a higher oil content. The longer，fuller，lighter and yellow seeds showed a higher palmitate content，while the bigger，fuller seeds with non-visible yellowness were associated with the higher oleic acid content. The higher contents of linoleic acid and lignan were observed in short，small and shriveled seeds. The bigger and yellow seeds were found with a higher content of linolenic acid. Therefore，this study revealed the correlation of flax-quality traits with seed morphological characteristics，which can provide theoretical basis in quality breeding of flax via selecting the morphological traits.