The aim of this study was to dicover whether there are differences in the complete behaviour pattern between seperated sex and mixed sex groups of horses. Further, differences in the social structure of the herd should be investigated. For this, observation was made involving a group of mares, a gelding group and a mixed sex group of horses, concerning their functional circle of social, movement, convenience, sexual and resting behaviour. Summarized, it was established that the geldings showed significantly more behavioural patterns of playing, walking, running and standing than the other groups. Of this there was notably more running in the springtime and more standing in the winter observation. In the mixed group the behavioural pattern concerning social standing and convenience behaviour was significantly of more duration than in the other groups. Whereby the social standing was only significant during the winter observation. On the other hand, the behavioural pattern of the mare group during the winter observation showed significantly more standing than in the mixed group. However, there was definatly more dozing observed in both the mare and mixed group as amongst the gelding group. Antagonistic behavioural patterns showed a accumulation in the mixed group. In detail it was possible to prove that significantly more threatning behaviour was shown by the horses in the mixed sex group, but there were significantly more hits observed in the seperate sex groups in winter. Altogether more dynamics through playing, walking, running and hitting could be observed in the gelding group. In the mixed group the geldings behaviour was more balanced by the presence of the mares, there was a defininte status and serious arguements did not envolve. In practice this proves that mares and geldings can be kept together in small groups. A combined group does not have, according to the enclosed study, any negative influence on the social structure of the herd.