One of the key challenges of managing very huge volumes of data in scalable Information retrieval systems is providing fast access through keyword searches. The major data structure in the information retrieval system is an inverted file, which records the positions of each term in the documents. When the information set substantially grows, the number of terms and documents are significantly increased as well as the size of the inverted files. In this research we implement to techniques of inverted file -posting list and Tries trees- on Arabic Language, then we will try to state the optimum technique to store the vocabulary according to the speed of retrieving queries from the collection of documents.