Molecular Biotechnology is now central to those various research fields grouped together under the heading molecular sciences. The primary objective of this work is to study the expression level of TESF-1. Spermatogenesis is a unique process of cellular differentiation. Transcription in germ cell is a regulated programme. The genes TSPY, TSSK-3 and CREM are acts as a transcription factor. TESF-1 is involved in spermatogenesis process. TESF-1 could be a germ cell specific gene. It contains a conserved leucine-zipper motif in a proposed DNA- binding domain. It may function as a nuclear transcription factor in spermatogenesis. the main function of this protein is not yet identified.In this study we proved that TESF-1 is expressed in Musmusculus. We hope that his work would find the patronage of researchers.Time alone will tell how sucessfull we have been.