Abstract: This paper proposes an object—oriented approach concerning data management and tool control to support design engineers for efficient interaction with their CAD system.A data model named DTO(Data and Tool 0bject)is offered to characterize a design object which is identified by four aspects：ObjectClass_id,Method,Version and Facet. A declarative description language is developed for design tool characterization. A dynamic design flow scheduling(DDFS)for tool control is realized with design eVent stack mechanism.DTO model together with DDFS can sufficiently meet most important requirements of a VLSI design framework：data consistence adminstration and hiding,Version control,hierarchical and equivalent representation of data,and automated design flow control.A gate array design framework is successfully established based upon these ideas and it shows promising results in real chip design.