The green synthesis of three 1,3,5-substituted (acetyl, propionyl and butanoyl) hexahydro-s-triazines was performed in various ionic liquids (ILs). The effects of the type and addition of IL, reaction temperature and time were investigated and discussed. The IL′s activity and selectivity depend on their acidity. The ideal ILs are sulfuric acid functional ones which could give a yield of target compounds up to 80% at 1 h reaction time. These kinds of ILs have selectivity of higher than 98%, and could be reused for three times without reducing activity. The characterizations of prepared ILs and triazine derivatives have been done with FTIR, ¹HNMR, MS and elemental analysis.