Based on the description of the backgrounds,sings and behaviors of El Nino,the effects of El Nino to the global climate and the climate in China were analyzed.It is pointed out that El Nino is only a natural phenomenon,and the climate is affected by many aspects.The effects of El Nino are very complicate and it is quite difficult to predicate the phenomenon accurately.For the sake of preventing and reducing the effects and loss caused by El Nino,we should enhance the ability on monitoring and prediction of the phenomenon.