This paper analyzed the contradiction of Born s probability explanation when particles of microcosm interference through an ideal experiment, proposed a new explanation about the wave-particle duality in microcosm, and described a test experiment that examed the new explanation.

The article thoroughly probes into the evolution and developing of interpretations of probability.

Discussing Pascal probability from the view of philosophy involves the following several issues: monism and pluralism, epistemological interpretations and objective interpretations, relations of probability and causality, the Hume\'s problem which puzzles philosophers at all times and adequacy of interpretations of probability.

In addition,the propensity interpretation also obviously overmachs the frequency interpretation in other aspects.