The processing and filing of letter numbers in the Plalangan Village Administration still uses the manual method, namely by recording (handwritten) in a book and reviewing the order of previous letters to number new letters. In this way it is certainly not efficient because it requires a thick book, especially if it is for recording for a long time and the many types of letters to be archived. With this problem, this research will create a computer system that is capable of storing these files into computer storage memory and is able to display letter numbers automatically so that archiving and numbering letters becomes more efficient. Sequential Search is a sequential search algorithm whose process compares each element one by one in succession, starting from the first element to the element being searched for, found or all elements have been checked. The purpose of this study is to implement the Sequential Search algorithm to facilitate the search for letter numbers in the case study electronic archive system of Plalangan Village Government. Overall, the results of this study support the successful implementation and performance of the Plalangan Village Government letter disposition system using the Sequential Search algorithm.