Developing the description and gaining an understanding of wind characteristics are important research tasks in wind engineering. Intermittency is one of the most important characteristics of wind. However, little literature is available on its quantitative measurement. In this study, wind speed intermittency is defined from the perspective of the physical nature of wind. According to this definition, the duty ratio of wind speed ramp (DRWSR) is proposed to quantitatively measure wind speed intermittency. Based on the measurement of wind speed intermittency, quantitative insights into intermittency can be obtained by analyzing the time series of the DRWSR, e.g., the intensity and variation pattern of wind speed intermittency in a day, which contributes to better understanding of wind characteristics. (C) 2016 Elsevier Ltd. All rights reserved.