  A framework for a quantum information theory is introduced that is based on
the measure of quantum information associated with probability distribution
predicted by quantum measuring of state. The entanglement between states of
measured system and "pointer" states of measuring apparatus, which is generated
by dynamical process of quantum measurement, plays a dominant role in
expressing quantum characteristics of information theory. The quantum mutual
information of transmission and reception of quantum states along a noisy
quantum channel is given by the change of quantum measured information. In our
approach, it is not necessary to purify the transmitted state by means of the
reference system. It is also clarified that there exist relations between the
approach given in this letter and those given by other authors.
