The different photoelectric signals in bacteriorhordopsin are experimentally measured when it is excited by 10 ns pulsee lasers at 1064 nm, 532 nm and 355 nm. 532 nm pulse laser is used mostly as pumping light to measure the photoelectric signals affected by the impedance of the measuring circuit. The mechanism that bacteriorhodopsin generates photo-charges and the photo-charges transfer in it was studied and analyzed. The results show that the positive and negative photoelectric signals are produced by the shift of the positive and negative charges respectively, and more energy is needed to produce positive charges than negative ones. At the same time, the positive and negative charges not only have their own transfering characteristics, but also affect each other, such as, positive charges move slowly, and negative ones fast, moreover, the negative can pull the positive to move forward, which, together with the interface between the sample and electrodes, cause the magnitude and width of the pulse photo-voltage having special dependence different from other photo-electronic devices on the linked resistance.