This paper discusses that there are two sorts of group consensus in Hall for Workshop of Meta-synthetic Engineering： draft consensus and decisive consensus, which are respectively formed in the two synchronous stages in the process of ＂synchronous stages 1- asynchronous stages- synchronous stages 2＂, and focuses on the concept of draft consensus. Then proposes a draft consensus building model and its solution method called Consensus Building Graph, by which claim concern value, claim support value, claim authority value and claim consensus value can be calculated real time for reaching a consensus, and designs a computer aided consensus building system called Internet based Group Discussion Environment. The model follows the methodology of meta-synthesis from qualitative to quantitative analysis in which computers and humans are combined to solve complex problems.
