Speculative computation is based on abduction, and it can give result of decision in advance based on defaults under incomplete resource information. To achieve goals and reduce risks of decision, master agent in speculative computation makes efforts to obtain more information via negotiation. However, the speculative computation and negotiation have usually deadlines. In this paper, framework extended of speculative computation with deadline is presented, and the further negotiation framework and negotiation algorithm under time constrainst are presented, the algorithm is embedded in speculative computation. The experiments have proved the algorithm can improve the accuracy of result of speculative computation, reduce the risk of the result.