Determination of dynamic characteristics of constructions is now demanded by GOST R 53778- 2010. It is a very important step to achieve safety of constructions. But GOST requirements do not pay attention to peculiarities of test procedures with unique objects. The comparative results of tests and analysis of dynamic characteristics of the constructions of Kroonstad Naval Cathedral being obtained during 2005 – 2009 are represented. It was established that some definite changes resulting in loss of spatial rigidness of the whole building occurred in condition of Cathedral constructions.