Chinese President Xi Jinping, accompanied by his wife, Peng Liyuan, greeted the SCO leaders with a handshake before a photo session.
The event begins on Sunday with a reception held for heads of national delegations in President Xi's name.
The SCO summit, the largest in history, is being held at the Meijiang Convention and Exhibition Center from August 31 to September 1. It is expected to draw more than 20 foreign leaders and representatives of international organizations.