With the development of energy storage in the regulation market, it is urgent to solve the impact of the decision-making behavior of alliance containing energy storage on the clearance result and the problem of the maximization of its own profit. First, the concept of degree of participation is proposed to explore the influence of the difference of declared power and price in the energy and regulation markets, and then a bi-level optimization model is constructed, which aims at maximizing the profits of the alliances and minimizing the cost of distribution system operator (DSO). Optimal bidding strategies of alliances in two markets are studied by employing path-following interior point algorithm and genetic algorithm, and Nash equilibrium of the markets is achieved. Testing results on IEEE 33-bus system demonstrate validity of the proposed method. The market clearing result and its own profit under the influence of different degree of participation are analyzed, and results show that reasonable selection of degree of participation can obtain higher profits.