This paper investigates the energy-efficient air conditioning supply chain, which is composed of one supplier (MIDEA) and two retailers, i.e. SUNING and GOME. With a view of market share, we measure the impact of retail prices variability in the two-echelon supply chain on the bullwhip effect. SUNING and GOME are assumed to possess the autonomy of choosing prices and separately acquire various market shares, according to which the relationship between the two prices is simply quantified. The order-up-to inventory policy and the moving average forecasting method are respectively employed by the two retailers. Furthermore, we cast light on how factors like price, market share, lead time, and autoregressive coefficient affect bullwhip effect. The results indicate that it’s inadvisable to conduct large fluctuation on price. Besides, demand dates that are more historical may actually reduce the bullwhip effect. We also find that the bullwhip effect will be bigger when the competition becomes fiercer, and there's a necessity for retailers to take measures to reduce the influence of competitors' prices.