Firstly，the paper reviews the theory foundations and basic models of information foraging theory, Then the paper divides the information scent into four types such as text，pictures，radios，and videos and designs the five rules concerned with the applying information scent to subject navigation website.  Lastly，the paper constructs the model of subject navigation website performances optimization based on information foraging theory and conducts a case study taking the American subject navigation website named Information as an example,