In order to research modulation schemes suitable for indoor wireless optical communication, the modulation structures of five modulation schemes (OOK, PPM, DPPM, DPIM and DH-PIM) are analyzed, the equations of average transmitting power, bandwidth requirement, transmission capacity and packet error rate are derived in detail, and the simulation results are given. In terms of average transmitting power, PPM achieves the smallest followed by DPIM, DPPM and DH-PIM, OOK achieves the biggest. With regard to bandwidth requirement, OOK achieves the smallest followed by DH-PIM, DPPM and DPIM, PPM achieves the biggest. As for transmission capacity, DPPM achieves the biggest followed by DPIM and DH-PIM, OOK and PPM achieves the smallest. Under the condition of the same modulation level, PPM achieves the smallest followed by DPIM, DPPM and DH-PIM, OOK achieves the biggest on the part of packet error rate.