"My view is that's not an appropriate way for a presidential candidate to behave," Bezos said at an event held by The Washington Post, the newspaper he owns.
Trump, the billionaire businessman, told Fox News last week that Amazon has "a huge antitrust problem." He accused Bezos of using the Post as a "toy" to help Amazon, the world's largest online retailer, get fair treatment from politicians.
"Amazon is getting away with murder tax-wise. He's using The Washington Post for power so that the politicians in Washington don't tax Amazon like they should be taxed," Trump contended.