Abstract: Rift Valley Fever Virus (RVFV), a phlebovirus of the family Bunyaviridae is a major public health threat in Egypt and sub-Saharan Africa. RVFV possesses a single stranded segmented RNA genome composed of a Large (L), a Medium (M) and a Small (S) segment. The M segment codes for a polyprotein which is the precursor to the glycoproteins G1 and G2 and two nonstructural proteins. The present study aimed to study the possibility of production a subunit recombinant viral G1 protein of RVFV, to use it as alternative immunogen. To produce subunit protein of RVFV, a seed stock of RVFV pantropic Menya strain (M/S/258) strain was obtained then titrated. A virus seed stock was prepared using Chicken Embryo Related Cells (CER) cell line. Specific primers for G1 gene containing BamHI and KpnI restriction sites were designed and used to excise the gene using RT-PCR technique. The PCR products were purified and ligated into plasmid (pCR®II-TOPO®) cloning vector. Transformed colonies were selected and tested for the presence of rG1 gene using miniprep, followed by restriction endonuclease digestion. Positive plasmids containing insert were subjected to DNA sequence analysis to confirm that the insert DNA is G1 gene. Insert 2 was prepared by digesting the expression vector pQE-30 with BamHI and KnpI restriction enzymes. Rapid screening of small expression cultures showed the ability of selected colonies to express rG1 protein. Time course and Isopropylthio-β-D-galactoside (IPTG) concentrations were tested to determine optimum time and IPTG concentration to be used in large-scale expression culture. Bacterial cultures revealed the presence of specific band at approximately 52 Kda in induced culture. Western blot analysis verified the presence and antigenicity of rG1. Large-scale production and purification of rG1 resulted in 6 mg protein. The produced recombinant viral antigenic subunit protein is a step to develop new, safe and effective vaccine.