The study found that the quality of hybrid middle rice seedlings is influenced by seedling density and age. As seedling age increased, the positive impact of density on seedling quality also increased. There was no significant effect on height, dry weight, and leaf area of seedlings. However, a negative correlation was observed between height and dry weight, as well as tillers of single seedlings and seedling density. The quality of seedlings started to decline at certain density levels, with optimal densities suggested for different sizes of seedlings. For smaller seedlings, a density of about 6400 plants per square meter was recommended for efficiency and higher yield.