Solar Ring (SOR) is a proposed space science mission to monitor and study the Sun and inner heliosphere from a full 360 degrees perspective in the ecliptic plane. It will deploy-three 120 degrees-separated spacecraft on the 1-AU orbit. The first spacecraft, S1, locates 30 degrees upstream of the Earth, the second, S2, 90 degrees downstream, and the third, S3, completes the configuration. This design with necessary science instruments, e.g., the Doppler-velocity and vector magnetic field imager, wide-angle coronagraph, and in-situ instruments, will allow us to establish many unprecedented capabilities: (1) provide simultaneous Doppler-velocity observations of the whole solar surface to understand the deep interior, (2) provide vector magnetograms of the whole photosphere - the inner boundary of the solar atmosphere and heliosphere, (3) provide the information of the whole lifetime evolution of solar featured structures, and (4) provide the whole view of solar transients and space weather in the inner heliosphere. With these capabilities, Solar Ring mission aims to address outstanding questions about the origin of solar cycle, the origin of solar eruptions and the origin of extreme space weather events. The successful accomplishment of the mission will construct a panorama of the Sun and inner-heliosphere, and therefore advance our understanding of the star and the space environment that holds our life.(c) 2022 COSPAR. Published by Elsevier B.V. All rights reserved.