Low-molecular-weight oil gelators have been attracting attention in recent years, because gelators suitable for various applications, such as gel physical properties, temperature characteristics, and stimulus responsiveness, can be developed through precise molecular design. In this paper, we introduce the gelling ability of long-chain alkyldiamide-type low-molecular-weight oil gelators (two types of gelators; dicarboxylic amidoamine-type oil gelators and asymmetric diamide-type oil gelators) for various oils, and the relationship between molecular structures such as alkyl groups and lipophilic groups and solution properties.