One of the possible approaches for quantitative study of 
a regulatory mechanism of living systems is considered. 
The equations of a state of  regulation system are constructed 
taking into account  a cooperation of processes, presence of 
a combined feedback and a temporary relations in a regulation loop.  
Results of the qualitative analysis of equations and their model 
systems have shown existence of following functioning regimes: rest,
stable functional state, periodic and irregular fluctuations. 
In some cases the "black hole" effect  - solutions collapse to a
trivial attractor is observed. The application of results of model
investigations for analysis of some biological problems shows,
according to our opinion, that the proposed method can be used for
quantitative study of  a mechanism of living systems at the norm
and anomalies.