Integrated Photonics, which has achieved great success since Integrated Photonics was proposed by Dr. Miller in 1969. Currently various materials and technologies have been developed to realize photonic integrated circuits for many applications. The comprehensive reviews for the state-of-the-art for all aspects of integrated photonics will be very helpful for this field. It is even more important to have a deep discussion on the challenges and perspectives for integrated photonics, which will be definitely very beneficial for the young scientists and students.