In this study, it is aimed to investigate the estrus behavior characteristics of cows by observing them comparatively and to reveal especially the sound related features in detail. For this purpose cows were observing during the oestrus time for their vocalization behavior. Oestrus affected by many hormones secreted by the animal during oestrus periods. There are several estrus detection methods, but efficiency differs depending on many factors. Efficient oestrus detection effect reproductive performance, while providing a significant increase in productivity in herd management and eliminating factors that inhibit reproductive performance. This research was investigated between February -May 2017 at Private dairy Farm which is located Mediterranean region of Turkey. At the beginning experiment, cows were selected depending on their characteristics as an example at the beginning of the experiment in order to minimize the experimental error and avoid the effects caused by the differences between the groups. Holstein milking cows which selected similar lactation number (3,1±0,84), body weight (664,69±7,45) and milk yield (25,96±0,49) were used. 150 head cows were synchronized with their estrus using the ovsych protocol and 10 cows were taken observation pen. The barn where the experiment is conducted is a free-stall barn and there are also walking areas for animals. Oestrus behavior of the cows was recorded by the researchers using directly observation methods. During oestrus period vocalizations behavior increased from 12,67±2,11 to 61,46±12,18 calls. During post oestrus period vocalization of cows decreased to 24,00±2,01. There are big variations between the cow vocalization. But cow calling; a statistically significant difference was found between the number of repetitions of sound; repetition was significantly longer in heat cows (p <0.01). Results suggest that more studies are required to draw strong conclusions regarding detailed information about oestrus situation of cow.