As a prevalent marketing strategy, bundling has made a great influence on the consumers' buying decisions. To reveal the inner influence mechanism of bundling strategy, a structural equation model is developed based on China Unicom iPhone contract plans. Then the influence of economic conditions, bundling type, pricing, satisfaction of bundled brands and bundling strategy on consumers' buying decisions are analyzed. The results show that all the above mentioned factors have a remarkably positive influence on consumers' buying decisions. Moreover, satisfaction with bundled brands and bundling strategy serves as the intermediary between pricing strategy and buying decisions.