Due to the unique biological features of original virus, HSV-1 derived vectors are rendered a number of advantages, such as broad cell tropism, including infection non-dividing mammalian cells across a broad range of species, and large capacity for foreign gene delivery. To date, two types of recombinant HSV-1 vectors known as replication competent vector and replication defective vector, derived from different HSV-1 strains, such as strain KOS and strain 17 have been developed as gene delivery vehicles and applied in fundamental studies and clinical trials for gene therapy. However, so far, no HSV-1-HF strain derived recombinant vector has been reported yet. Since the features of HSV-1 vectors are largely associated their original virus strains, the HSV-1 vectors from different strains may vary in their infection ability, tropism and cytotoxicity. Here, we described the construction of a HSV-1-HF strain based replication defective vector by a homologous recombination approach in bacteria. [Li Xiang, Xinjing Liu, Huitao Liu, Zhiqiang Han, Jiameng Lu and Yuming Xu. Construction of HSV-1 HF based replication defective vector. Life Science Journal. 2011; 8(3):547-553] (ISSN: 1097-8135). http://www.lifesciencesite.com.