The lowest bidding method is the best bid evaluation method theoretically. However,it has some problems such as low price and low quality,malicious claims and so on. Therefore,it is significant to set up a scientific implementation system of the lowest bidding method. Based on the domestic and foreign researches and the status quo of the construction industry in our country,this paper analyzes the root causes of the lowest bidding method, including design changes, cost uncertainty and difficult quality cont...