The author investigated the actual state of empty and matured seeds as a part of the fundamental researches concerning the propagation of japanese lawn grasses by means of seedlings in 1951, and at the same time he examined into the reliability of the pertinent selecting methods of seeds, which he had selected from among many methods. In this case wild and cultured varieties of Zoysia japonica STEUD. were employed, the selection of seeds being practised by alcoholic and wind selection methods. 1. It has generally been considered up to now that empty seeds will be produced so much in case of seedling propagation of Japanese lawn grasses that the propagation method is almost impossible, but a considerably high percentage of matured seeds has been obtained by this experiment. 2. The maximum and minimum percentages of matured seeds of Zoysia japonica STEUD. were 93.7% (wild plants) and 77.9% (cultured plants) respectively, and averaged 86.2%, which shows a satisfactory result for the practical use of seedlings. 3. As for the maturity percentage the wild variety is the better of the two. The higher maturity percentage was obtained by the early ripened seeds than the other. 4. All the seed were matured seeds which sank into the bottom in case of alcoholic method of 65〜85 percentage solution, the amount was 71.60f the total matured seeds. (86.3Invalid or incomplete multibyte or wide characterax. value and 57.3Invalid or incomplete multibyte or wide characterin. volue.) 5. In case of wind selection of 250cm/sec the seeds which travelled less than 30cm from the dropped place of seeds were all matured ones, the amount of which was 91.527777735000f the matured seed. (94.74Invalid or incomplete multibyte or wide characterax. value and 88.3Invalid or incomplete multibyte or wide characterin. value.)