Abstract: In recent years, cesium based inorganic perovskites (CsPbX₃) are of great interest due to their high thermal resistance, low cost and tunable bandgap, which have been used as absorbers to for the development of novel thin-film solar cells. Currently, the photovoltaic performance of inverted perovskite solar cells (PSC) still leg behind that of regular solar cells, though the inverted solar cells are more stable and more promising as top layer of tandem solar cells. Therefore, the device structure of inverted solar cell remains to be further optimized. To approach this aim, researchers have developed a series of organic and inorganic interfacial layers, including hole-transport-layer and electron-transport-layer, with the aim of optimizing the inverted inorganic perovskite solar cells. Herein, we address the recent progress of organic and inorganic interfacial layers from the perspective of materials and processing techniques. A variety of material systems are compared to summarize their features. This work also discuss their bottlenecks and try to provide potential solutions for achieving ideal interfacial layers.