NOVELTY - A minor cycle sequencing batch reactor system comprises a cylindrical-shaped host reactor, a water inletting system, a water discharging system, an aerating system and an autocontrol device. The water inletting system comprises a water inlet (1), a water storing trough (2), a peristaltic pump (3) and autocontrol device (12). The water discharging system comprises a water discharging solenoid pilot actuated valve (6) and autocontrol device. Culture is controlled in the system and the pH value of the treating system is adjusted by adding supercarbonate.    USE - System for culturing aerobic granule sludge and treating organic wastewater (claimed).    ADVANTAGE - The aerobic granule sludge can be cultured rapidly and economically, and the treating effect for the organics, nitrogen and phosphorus in the organic wastewater is great.    DETAILED DESCRIPTION - Minor cycle sequencing batch reactor system comprises a cylindrical-shaped host reactor, a water inletting system, a water discharging system, an aerating system and an autocontrol device. The water inletting system comprises a water inlet (1), a water storing trough (2), a peristaltic pump (3) and autocontrol device (12). The water discharging system comprises a water discharging solenoid pilot actuated valve (6) and an autocontrol device. The aeration system comprises an air compressor (9), an aerator (10) and an autocontrol device. The autocontrol device is a microcomputer time-controlling switch or programmable logic controller. Culture is controlled in the system and the pH value of the treating system is adjusted by adding supercarbonate. INDEPENDENT CLAIMS are included for:    (1) a method of culturing the aerobic granule sludge and treating wastewater by using sequencing batch reactor mode operation comprising four stages of water inletting, aeration, precipitation and water discharging; and    (2) an operation method of minor cycle mode.    DESCRIPTION OF DRAWING(S) - The drawing is a schematic sectional view of the minor cycle sequencing batch reactor system.    Water inlet (1)    Water storing trough (2)    Peristaltic pump (3)    Actuated valve (6)    Air compressor (9)    Aerator (10)    Autocontrol device (12)