President Nicanor Duarte alleges that "China has not even invested 15 percent of all the investments it promised."
He did not elaborate, but said China had not cooperated with Paraguay during his term in office, which ends in August.
Duarte's blast seemed to be largely aimed at President-elect Fernando Lugo, who says he plans to establish diplomatic relations with China.

Until now, Paraguay has always had relations with Taiwan, which China considers a breakaway province.
China and Taiwan have battled for influence in Latin America with investment, trade and aid.