The evaluation of the information requirement and the workload is a part of Periodic Safety Review (PSR) for Nuclear Power Plants (NPPs). The information requirement means detail elements of the essential information during performing some tasks. And also, the workload can be defined as the amount of work per hours during the operation of those tasks.The purpose of this study is to estimate the correlation among the basic factors for working conditions, which include the information requirement and the workload, and to offer basic information of working environments. The basic factors include the frequency of task, the importance of task, number of working person, the time consumption for working, the working environment, the assistant of tool, and the requirement level of training to perform the task. The basic factors of working conditions were composed by technical references. We used 179 tasks (in 3 sites) which were selected from the officially managed procedures and related to the safety and representation of each division.