"We're clearly spending less than Didi in subsidies," said Uber founder and CEO Travis Kalanick, referring to the homegrown market leader Didi Kuaidi.
"We're spending less per trip, and we have a larger balance sheet."
Both firms raised billions from investors last year as they try to secure their positions in the fiercely competitive market, offering both drivers and passengers subsidies that have proved a boon to Chinese consumers.
The Uber CEO told a press conference announcing a partnership with Chinese conglomerate HNA Group: "Our best information now is Didi is spending 70 to 80 million US dollars per week in subsidies, that's almost four billion a year.
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"In the last year we've gained significant market share in China, and spent far less than that. It's not just about how much you invest, it's also about how efficiently you invest it."
Uber China was established last year and has so far committed to spend roughly USD 1 billion in the country, where it says it is currently active in 22 cities.
"We are making significant investments in dozens of cities here in China, and at some point it will be hundreds of cities here in China," Kalanick said.
But the Silicon Valley company - which has partnered with China's largest search engine company, Baidu - still lags Didi Kuaidi, which was formed from the merger of two firms backed by the Chinese Internet giants Alibaba and Tencent.
Didi says it has operations in 199 cities. According to a report by Beijing-based Analysys International, in the third quarter of 2015 Didi Kuaidi commanded over 83 per cent market share of active users in China, compared to Uber's 16.2 per cent.
Didi Kuaidi spokesperson Sun Liang told AFP: "Uber is being wildly creative about our numbers.
"Didi holds over 80 per cent of the market, which means our competitor has to bleed subsidies to make up for inadequate numbers of riders and drivers," she said.
"Our numbers show we are maintaining 10 times as big a rider/driver network at one fourth of the rival's unit cost.