To meet the needs of the company, security issue and M&A have become the most important way of financing. Due diligence is the key factor of those activities. Through independent financial and legal due diligence, the buyer/investor get better known about targets in the aspects of financial highlights, operating level, profitability, solvency and their statements. And they can also estimate the feasibility of acquisition or investment so as todecrease cost and avoid risk. At the same time, seller/invested can also avoid the interest damage. So it is very important to process due diligence before M&A.