In view of the characteristic of changing qualitatively into build-and-fix model by the bad control,which is a universally existing problem about these software development models,such as rapid application development (RAD) model,incremental model,and agile software development,a new kind of model by the name of incremental story iteration model on rapid application development (ISI-RAD)was presented based on agile software development.With the process segmentation and the incremental sequence generation,the project schedule pool and the bug state pool were used to construct the story iteration.The project schedule pool can be responsible for tracking the software system development schedule,and the bug state pool can be responsible for loading the code bug feedback to evaluate the later quality,and then the efficiency of software development can be improved.Good results were achieved in practical application of ISI-RAD to an example.