Abstract: With the development of the global economy, high-quality jewelry has increasingly become an important category of investment and collection. Auction is an important carrier of high-quality jewelry transactions and the level of auction prices is the vane of the future price of jewelry. Studying the global colourless diamond product auction market will provide reference and data support for jewelry practitioners or consumers to grasp the global colourless diamond products auction trends or make colourless diamond investments. This research collects and organizes the colourless diamond lot information from 2008 to 2018 published by the eight world's largest auction houses and analyzes the lot structure, price, auction houses and place of transaction. The research draws the following conclusions: (1)The share of high-quality colourless diamonds in the auction market is increasing over the past 11 years; (2)The carat unit price of colourless diamonds is obviously affected by the world macroeconomics; (3)Colourless diamond carat unit price is positively correlated with carat weight; (4)Christie's colourless diamonds are of higher quality than Sotheby's and Bonhams; (5)Online auctions currently make a small contribution to the overall global colourless diamond products auction transaction volume, but they have great potential.