In wave mechanics of quantum theory, the involved wave function in the Schro ̈dinger equation is treated as the probability of deflected particles in some spatial region, which is fundamentally different with that of the statistical mechanics in the framework of classical physics. Consequently, the understanding of the quantum probability and its relation to the definite value reported by the measurement becomes the core problem to understand the quantum measurement. In this paper, we discuss the interpretations for quantum probability from the point of view of determinism and empiricism.