Abstract: Provided are a method of preparing, and use of 1-(2,2-dimethylpropyl)-cyclopropene as an ethylene antagonist that can be formulated as an aqueous emulsion and applicable to plants through immersion or spraying. It was confirmed that the compound can be reliably synthesized and stored by the preparation method disclosed herein, and it was also confirmed that the compound can effectively inhibit ethylene action when formulated as an aqueous emulsion and treated to a plant by immersion or spray treatment; hence, the compound may be used as an ethylene antagonist on plants, as a pre-harvest or post-harvest plant growth regulator, or as a freshness keeping agent.