We focuse on design process in concurrent engineering and propose an approach to collabora-tire design based on distributed constraint-net. The approach adopts agent technology to express kinds ofdistributed constraints. And through the cooperation among agents, the consistency of constraint is main-tained and the constraint conflict is detected and eliminated. The constraints are satisfied concurrently anddistributively. Based on the proposed approach, the collaborative design process in concurrent engineeringcan be well supported.