As many scholars know, the scope of the Ssu-k'u ch'uan-shu is enormous, making it an extremely convenient reference source. However, limitations at the time it was compiled resulted in many lacunae and errors. The original in the National Palace Museum as well as its supplementary materials is a complete edition. By conducting a restoration of the primary nature of the Ssu-k'u ch'uan-shu, its value as a historical source can be further raised and continue to provide reference for the scholarly community. As a result, supplements are an on-going process. Since different editions of the texts found in the Ssu-k'u ch'uan-shu exist and are found scattered in across libraries, this work is often very tedious, time-consuming, and difficult to accomplish at one time. This paper attempts to present scholars with an overview of the supplements here. The article not only offers an objective retrospective on the work of previous Ch'ing editors and compilers in the Ssu-k'u (Four Treasuries) Library at the palace, but also a detailed report on the processes and difficulties involved. Finally, it is hoped that following generations of scholars will continue improve this important compilation.