The heart rhythmical activity is characterised by the deterministic chaos which can - reflect the organism adaptation differing by individuality. In this respect it is very interesting to investigate the chaos in the heart activity dynamics of different psychotypes, the organism of which does not react identically on the extreme factors of the environment including biorhythmological criteria, for example, at the macrolevel in е daily dynarmics of the physiological indexes. So the aim of this work is the investigation of the daily dynamics level of the ECG chaos in its dependence on extroversion level, neuroticism and personal anxiety. Ten heaithy volunteers were investigated. The ECG data were registered 6 times during the day with an interval of 4 hours, they were taken with the second standard ECG leads in an automatic regime. The measures were taken with 5 repetitions. The chaos analysis was done by the method of the attractor construction and the value of its dimension. The comparison of the ECG attractors geometry taken in the different psychotypes demonstrated the individual differences in the mobility of the attractors structures during the repeated measures: the largest stability of the phase ECG portrait was discovered among the volunteers having the low level of neuroticism. The obtained results also proved that the mean daily fractal dimension meanings were truly higher in the unstable, anxious and extrovert groups (especial in the emotionally unstabled groups). The daily dynamics analysis of the investigated parameter demonstrated the clearly marked daily rhythm of the chaotic level in the high-anxious groups which are unstable in all dimensions. This index was stable in all repetitions during the day in the groups of low-anxious and introverts but in the groups of extroverts and stables the well-expressed daily rhythm was exposed only in one measurement. The maximum chaotic ECG was registered only in the morning hours and more stabled ECG in the day time and in the evening hours. The sufficient differences in the position of maximum of the fractal dimension attractor index in the investigated groups were not discovered. That is why the plasticity of the behaviour correlates with the peculiarities of the biorhythmostatus both at the macro- and microlevels.