The purpose of formulating optimal decision on integrated marketing communications is to explore the best pattern of advertisement expense.On the basis of the optimal control theory,the optimal characters of expenses on two advertisement media are analysed.Under some particular hypotheses,the relative quantitative relationship between the two expense densities and the changing law of expense density in a particular interval are examined.The conclusions show that the expenses of two media relate to the synergy as well as the effect of accumulated value of sales.The gap between the results of normal analysis and the reality is pointed out.