The primary methods of stock investment analysis are fundamental analysis ,technic analsis and portfolio investment analysis.Based on analyzing the applicability and limitation of these methods, the paper is applying the cluster analysis in the stock investment, and pointing out it is a feasible and effective way to give advices to stock investment. Cluster analysis firstly looks into the industry factor, company factor, profitability and pullulation of each stock, so people can discover the investment value through stock'immanent value which is decided by their fundamental characters.To gather the similar stocks,a synthetic evaluation index system is erected to measure the similarity of stock all-roundly and objectively. Cluster analysis can help investors hold the whole character of stocks, make certain of investing scale and suppose the possible variation of stock price.So it will be easier for investors to choose investing occasion.