Charge polarization is an interesting and vital phenomenon in nature. This is the first report of such effect in crystalline red phosphorus (P). We synthesized large-scale (up to 100 x 10 x 0.3 mu m(3)) single crystal red P microbelts (PMBs) in the presence of bismuth (Bi) nanodroplets via a thermal vaporization method. Under visible light illumination, the PMBs become highly polarized. Electrons accumulate at the two ends of the microbelts which become negatively charged, while the middle section is positive. In an aqueous solution, the PMBs can trigger water reduction to produce hydrogen at their negative-charged ends. Compared with 4where charge carriers are randomly distributed, the highly-polarized PMBs exhibit ten times enhancement in photo catalytic hydrogen production. An explanation for this interesting light-induced polarization effect is provided based on experimental results and theoretical calculations. This work may shed new light on the future development of high-efficiency P-based photocatalytic devices and systems.