China was the largest market for Japanese copper exports, with a 41 percent share, up from 32 percent in June, while Taiwan's share slipped to 20 percent in July from 42 percent in June.
China's copper imports rose 9.5 percent to a six-month high in July as material purchased during a period of lower prices in May and June arrived at ports.
Indonesia and Thailand are also key markets for Japan's copper.
Demand for copper, used in utensils, construction materials and computer chips, is often seen as a gauge of economic activity.
Japan's output of rolled copper product dropped 4.1 percent in July from a year earlier for a second consecutive month of falls, while copper wire and cable shipments fell 7.5 percent year-on-year in July to the lowest on record for the month, due to sluggish demand from auto and chip makers.
Copyright Reuters, 2011