Abstract: The experiment of "cat" designed by Erwin Schrödinger is to indicate that there is a paradox when we understand the quantum measurement based on classical realism. His quantum entanglement is to sketch the specialty of quantum measurement and to reveal that the knowledge of quantum system as a whole cannot be reduced to knowledge of its constituents. Quantum entanglement is not to prove that "material is based on consciousness", which goes beyond the scope of science. We must distinguish scientific issues from philosophical and religious ones when we want to understand quantum measurement. The confusion of these issues will make the discussion neither scientific nor convincing.

Key words: quantum measurement, quantum entanglement, Erwin Schrödinger, consciousness