The present invention relates to the intermediate compounds for preparation of agomelatine, as well as the preparation methods thereof The intermediate of the present invention for preparation of agomelatine is compound A as shown in the following formula. Also provided are two novel intermediate compounds. When we use these new intermediate compounds to prepare agomelatine, it is simple to manipulate, well-controlled and with high purity, without complicated operations such as rectification and column chromatography separation, and suitable for industrial production. Meanwhile, the preparation methods of the two new intermediates themselves is simple and high yield, only using the most commonly-used 7-methoxy-tetralone as original starting material and undergoing one step of reaction to obtain the intermediates, followed by one more step of converting the intermediate compounds to desired product agomelatine. Said reaction processes are greatly simplified, with the reaction yield being improved and the difficulty in purification of previous method being overcome, as compare with the previous technique for preparation of agomelatine. Typically, the yield of the present invention is over 70%.