"Don't let [Chinese President Xi Jinping] play you," the New York Democrat said in a tweeted statement.
Schumer's message comes as top Trump administration officials meet with Chinese Vice Premier Liu He about striking a possible agreement to reduce trade tensions between the world's two largest economies. The second day of talks takes place in Washington on Friday after a series of meetings on Thursday, including one which Trump attended.
China's Foreign Ministry denied on Friday that it offered to reduce its trade surplus with the U.S. by $200 billion, as reported by news outlets. Trump has long contended China takes advantage of the U.S. because China sends significantly more goods to America than the U.S. sends back.
Schumer appeared to reference those reported terms in his statement Friday. He urged Trump not to give up on his effort to punish Beijing for alleged theft of intellectual property by Chinese companies.
"Trading some short-term purchases of American goods and giving up on China's theft of American intellectual property (which are our family jewels that will create millions of good paying jobs) is the art of a bad deal. Stand strong," he said.
Trump has floated tariffs on $50 billion worth of Chinese goods such as electronics and machinery in response to alleged intellectual property abuses. He proposed an additional $100 billion in tariffs on other Chinese goods.
China floated retaliatory tariffs on U.S. goods such as crops and aircraft. The possible Chinese measures sparked concerns about damage to the U.S. agricultural industry.
Some free-trade lawmakers and market watchers hope the talks will avoid escalating tariffs and a potential trade war. On Thursday, Trump said he doubts the negotiations with China will succeed.
"Will that be successful? I tend to doubt it," the president said. "The reason I doubt it is because China has become very spoiled. The European Union has become very spoiled. Other countries have become very spoiled, because they always got 100 percent of whatever they wanted from the United States."
Trump's comments sparked fresh concerns among traders and investors on Thursday, when the Dow Jones industrial average ended the day down about 50 points.
Trump has also faced backlash on Capitol Hill for reports that the U.S. could consider a deal in which it would lift a ban on American companies selling to Chinese telecommunications company ZTE in exchange for China scrapping tariffs on agricultural products. The ban on ZTE came in response to the company's shipping of American goods to Iran and North Korea in violation of sanctions. It effectively crippled the firm.
On Wednesday, Trump contended his decision to ask his Commerce Department to find a way to aid ZTE did not constitute "folding" to China's suggestions.