Defect Generation in hydrogenated amorphous silicon has been investigated through photocurrent decay due to light soaking with constant intensity (CFC) and in constant photocurrent condition (CPC). The decay of photocurrent under CFC can be explained well both with the model of Stutzmann and with that of Redifield and Bube. That means that the decay agrees with one third power rule predicted by the bimolecular recombination model of Stutzmann and also follows the stretched exponential derived by Redifield and Bube. Under CPC, however, in which the intensity of soaking light is increased to maintain consta photocurrent, the kinetics of defect generation seems to obey the stretched exponential. A modification of the rate equation of defect generation has been attempted to account for large value of $\beta$, which is in consistence with the enhancement of hydrogen diffusion in the presence of excess carriers. The photocurrent decay under both CFC and CPC light soaking was carried out at various temperatures in the range of 180K and 346K. The effect of temperature, which is expected to help to surmount the barriers against defect conversion, seems to be compensated above room temperature. The reduction of band tail carriers at elevated temperatures under constant intensity illumination may cause the compensation, lessening the effective activation energy ofr SWE. Finally it has been found that photocurrent decay at low temperatures is not consistent with the existence of the local temperatures.