In order to address the trade-off problems between time and cost in the grid workflow scheduling with deadline constraints, this study proposes a new algorithm named path balance (PB) to adjust the length for each path in workflow and develop a heuristic referred as path balance based cost optimization (PBCO). PBCO makes full use of the workflow cost optimization space by setting a deadline for each task, based on the results of PB, and enlarges the optimization space for multitude tasks by distributing the redundancy time, based on the quantities of tasks at each level, this is divided by using the bottom level strategy. According to the experimental results, the average execution cost of PBCO decreases by about 35% relative to other famous heuristics, such as DET and DBL.