Summary: This paper discusses the problem of maximizing brand’s market share by proper allocating budget to the activities of sales promotion and loyalty program while total budget for marketing activities is constrained. For that the brand choice of customers in a market is always influenced by marketing activities of sales promotion and loyalty program, an enterprise needs to invest some capital to those activities to gain a larger market share. By collecting the data of promotion effect and the loyalty effect of all brands obtained from the market panel in previous periods, a Markov type market share model is constructed. Under such a model and a budget constraint, the paper derives the amount of budget allocated to sales promotion and to loyalty program for gaining a maximized market share, and shows the maximum growth ratio of market share at the next period.