The present invention relates to a control method of a washing machine. In the control method, detecting the wash water turbidity and determining a devoted washing agent amount by using said turbidity, further regulating at least one of washing and rinsing programs based on said devoted washing agent amount. Furthermore, judging whether adding the washing agent based on said devoted washing agentamount. According to the invention, it is capable of maintaining a certain washing force and shortening a washing time for washing articles to be washed so as to save power consumption for washing.