In this study we will discuss our cross language text retrieval (CLIR) experiments of Persian ad hoc track at CLEF 2008. Two teams from University of Tehran were involved in cross language text retrieval part of the track using two different CLIR approaches that are query translation and document translation. For query translation we used a method named Combinatorial Translation Probability (CTP) calculation for estimation of translation probabilities. In the document translation part we used the Shiraz machine translation system for translation of documents into English. Then we create a Hybrid CLIR system by score-based merging of the two retrieval system results. In addition, we investigated N-grams and a light stemmer in our monolingual experiments. Categories and Subject Descriptors H.3.3 [Information Search and Retrieval]: Information filtering, Query formulation, Retrieval models, Search process. Keywords Persian English cross language, Farsi bilingual text retrieval.