Abstract: Assemble-To-Order system as a vital strategy has been widely used by many manufacturing firms. A problem of asymmetric cost information is considered in assemble-to-order supply chain comprised of two component suppliers and single manufacturer. Based on the profiles of every members under complete information, the loss of vertical manufacturer and horizontal complementary supplier are analyzed due to "information disguise" from supplier who has private cost type information, and vertical supplier-manufacturer contract is presented based on incentive compatibility and cross-coordination contract with horizontal complementary supplier's participation. And the menu of contract is incentive feasible if it satisfies both incentive compatible and participation constraints.
Through mathematical deduction and data analysis, using Excel VBA programming to simulate models and data example, the result shows that:(1)under complete information, manufacturer can occupy all profit of supply chain, upstream suppliers' reservation revenues are zero.(2)under asymmetric information of supplier's cost, single supplier's information disguise not only reduces vertical manufacturer's profit and horizontal complementary supplier's profit, but also is harm to global benefit of supply chain.(3) the vertical incentive contract which is offered by manufacturer to asymmetric information supplier, can reveal the true cost information of asymmetric information supplier, and increase expected profits of vertical manufacturer and complementary supplier. But that cause "low efficiency downward distortion" effect which decreases the horizontal supplier's optimal order quantity.(4) The cross-coordination of sharing information rent between manufacturer and horizontal symmetric information supplier can reveal true cost type information and increase optimal order quantity and global profile of whole supply chain.
Above results fill the gap in the literature of ATO supply chain and incentive contract. And the managerial insight suggests that supplier need to cross-coordinate not only with vertical manufacturer, but also with horizontal complementary supplier.

Key words: information asymmetry, incentive compatibility, cross-coordination, assemble-to-order