However , the oldest preserved soybeans resembling modern varieties in size and shape were found in archaeological sites in Korea dated about 1000 BC .
Some scholars suggest that soybean originated in China and was domesticated about 3500 BC .
The oldest preserved soybeans resembling modern varieties in size and shape were found in archaeological sites in Korea dated about 1000 BC .
Some scholars suggest that soybean originated in China and was domesticated about 3500 BC .