The purpose of this study is to investigate the effects of oxides (caryophyllene oxide, eucalyptol and linalool oxide), one of the major ingredients of essential oils, on odor intensity, electroencephalography (EEG) response and emotional response. The subjects were women in their twenties. Inhalation concentrations of oxides were varied from 0.01 to 10%, and EEGs were collected by Quantitative EEG. The odor intensity and average preference index (API) of the oxides were ranked in the order of eucalyptol > linalool oxide > caryophyllene oxide. Eucalyptol is a refreshing and pleasant substance that activates the brain (activation of β and γ waves and spectral edge frequencies (SEF50 and SEF90)). Linalool oxide has a calm and soft substance (activation of θ, inactivation of α, β, and γ waves) at a low concentration (<0.1%), and a fresh smell at high concentration (inactivation β and activation of θ and γ). Caryophyllene oxides were evaluated as a substance that is comfortable, soft, calm and sedating, which deactivates the brain (activation of α, inactivation of β and γ). Oxide materials showed a positive correlation between the odor intensity and the SEFs. Each of the oxides showed unique characteristics in the areas of odor intensity, emotional response, API, and EEG. These results give us a better understanding of the properties of the pure materials that make up a fragrance, and provide useful information for the manufacture of fragrance products or aroma oil blends with enhanced specific functions.