  In this paper Quantum Mechanics with Fundamental Length is built as a
deformation of Quantum Mechanics. To this aim an approach is used which does
not take into account commutator deformation as usually it is done, but density
matrix deformation. The corresponding deformed density matrix, which is called
density pro-matrix is given explicitly. It properties have been investigated as
well as some dynamical aspects of the theory. In particular, the deformation of
Liouville equation is analyzed in detail. It was shown that Liouville equation
in Quantum Mechanics appears as a low energy limit of deformed Liouville
equation in Quantum Mechanics with Fundamental Length. Some implications of
obtained results are presented as well as their application to the calculation
of black hole entropy.
