The current driven MHD mode has been studied in LHD plasmas. When the Ip reaches a certain value, the energy confinement degrades without any noticeable precursor. The electron temperature profile shows a large flat region, which leads to the modification of the profile mainly in the core region. The attainable current becomes lower with increasing beta, which is consistent with the prediction of the MHD stability analysis. However, there are quantitative differences of the attainable current between the experimental results and theoretical predictions. Taking into account the beam pressure, the MHD analysis shows that the m/n=1/1 mode is destabilized and the current driven term is comparable to the pressure one. A similar behaviour of the collapse is also observed in a configuration whose magnetic hill is extremely large. For further research of the current driven mode, it is necessary to produce a higher field plasma to reduce the beam pressure component.