He calls them currency manipulators
Trump believes that the Chinese manipulate their currencies to sell more goods. He promised, in one of his speeches, to force a 45% import tax on their goods.
He thinks they waged an economic war
In many of his speeches Trump mentioned that china has waged an Economic war against the united states which resulted in ripping the united states off.
Large trade deficit with China
Trump doesn’t like the fact that the US has a trade deficit with China of $500 billion a year. He wants to change that.
He thinks they don’t respect treaties
Donald Trump said in one of his speeches that the US is not getting a fair treatment from China as they don’t respect economic treaties.
He thinks the US is too dependent on them
Trump said that the US is so dependent on China and he doesn’t like that.
He thinks they can control North Korea
Trump said in one interview that he knows that China can solve the North Korea problem and that without them North Korea won’t have food to eat. He thinks China is being manipulative by saying that they can’t convince the Koreans to do what they want.
They take Afghanistan’s minerals
In one of his speeches Trump said that Afghanistan is very rich in minerals and while the US is losing men, China is collecting those minerals from the other side of the mountain.
Killing American companies
Trump believes that as a result of China’s trade practices they are actually killing many of the american companies and ruining the US economy. (See Why did China devalue its currency in August 2015?)
Loss of US jobs
Trump said that the US has lost between 4 and 7 million jobs because of Chinese practices. He was referring to how Chinese companies flood the US with cheap products.
Some people suggest that Trump’s feelings towards China result from the belief that they are a big military threat.
They are the biggest competitor to the US
The fact that China is rising fast has made them the biggest competitor to the US in many fields. Trump wants to restore US leadership again. (See Why do some people want to migrate to the United States?)
Why Donald Trump hates China?
Does Donald Trump hate China? Donald Trump’s love-hate relationship with China