Abstract: Natural products have become an important source of new drugs. However,there are some deficiencies while producing complex natural products by classical organic synthesis,one measure to efficiently make up those deficiencies is to apply synthetic biology in the biosynthesis of natural product,i.e.,designing and reconstructing efficient biosynthetic pathways of target compounds,re-engineering it in host cells,and producing target compounds by fermentation. However,achieving the yield of target product to the industrial level through technology of synthetic biology is still very challenging though there have been advances in synthetic biology. Here,we review various pathway optimization strategies for the synthetic biological systems of natural products. Via optimization technologies of fine-tuning individual component,exogenous metabolic pathways,the chassis systems,and fermentation conditions,the synthetic biological system may be optimized,and the yield of target product may be maximized,thus providing continuous,stable and economical raw material supplies for the manufacture of complex natural products while source is rare,and promoting the research and development of new drugs similar to natural products

Key words: natural products, synthetic biology, optimization, chassis