The present invention relates to a co-expression vector that comprises both truncated von Williebrand Factor (vWF)-Fc DNA construct and B-domain deleted FVIII DNA construct in the same vector. By co-expressing FVIII and truncated vWF-Fc with one expression vector in cells, the present invention controls the ratio of gene templates for FVIII and vWF proteins, provides a higher protein ratio of FVIII to vWF during cell expression, that results in a better occupancy of FVIII in vWF, and creates a higher yield (>；1000 IU/ml) and more stable expression of FVIII protein molecules. In one preferred embodiment, the truncated vWF contains mutations of cysteines in the D′；D3 domain of vWF to reduce multimer assembly of recombinant vWF during expression, and thus increasing recovery and quality of FVIII.
