The suprachoroidal space (SCS) is the potential space between the sclera and choroid.Drugs delivered through SCS can bypass the sclera,avoiding clearance by conjunctival and scleral blood vessels and lymphatic circulation,so that more drugs can reach the disease tissues such as choroid and retina.SCS drug delivery does not disrupt the ocular integrity,is safer than the intravitreal drug injection and more effective than trans-scleral drug delivery.In addition,SCS delivery only needs a very small volume of drug,which makes it possible to be carried out in multiple parts of the sclera,and the specific disease area can be more precisely targeted.SCS drug delivery is suitable for the treatment of choroidal and retinal diseases.However,currently SCS drug delivery is still a novel field and many aspects need to be more in-depth studied,including its safety,delivery methods,drug formulation and effectiveness.