We studied two research items that can be undetermined issues in the artificial seed production of the Japanese scallops, Patinopecten yessoensis, batch-specific quality of the reproductive outputs and nursery acclimation, in the embayed waters of Yangyang, Gangwon, Korea. The first batch of the spawner showed better results in terms of survival, growth, and resistance against parasitic ciliate infection over the second batch that was obtained in 5 days after first batch from the same spawner. The early attached spats directly placed in the farming ground (the unacclimated) were resistant against the water current of the open environment, by showing survival of about 80% for a month, a normal survival compared with other results. However, the spat survival during the nursery acclimation was significantly lowered in comparison with that in the unacclimated condition (P<0.01). We discussed the research results of the two items, particularly focusing on their availability for mass seed production for aquaculture in the Korean coastal waters of the East Sea (Sea of Japan).