Low production of rice and horticultural crops can be caused by the limited supply of high quality seeds. The quality can be seen from the moisture content, viability value and seed vigor. One of the efforts that can be made to maintain or improve seed quality is seed coating technology. This study aims to determine the effect of seed coating in maintaining and improving the quality of rice seeds, TSS merang onion seeds, red chili seeds, and cucumber seeds. The research was conducted from November 2021 to January 2022 at the Technical Implementation Unit (UPT) of Rice and Palawija Seed Development Singosari, Malang, East Java. The experiment used a completely randomized design (CRD) with a single factor, namely the type of seed coating material. The seed coating materials for rice seeds were CMC 1.5% + Liquid Smoke 0.5% + CaCO 3 8 g + Gypsum 32 g, CMC 1.5% + Liquid Smoke 0.5% + CaCO 3 8 g + Dolomite 32 g, and CMC 1.5% + Liquid Smoke 0.5% + CaCO 3 8 g + Kapur Tohor 32 g. While the seed coating materials for TSS shallot seeds, red chili seeds, and cucumber seeds were CMC 1.5% + Humic Acid 0.6% + Gypsum 20 g. The results showed that the composition of the coating material CMC 1.5% + Liquid smoke 0.5% + CaCO 3 8 g + Gypsum 32 g produced the highest quality of rice seeds, while the coating material CMC 1.5% + Humic Acid 0.6% + Gypsum 20 g could improve the quality of TSS onion and cucumber seeds.