Abstract: Tortuous are the basic properties of the coastline, whichseriouslyaffect the natural marine environment and economic development. With the help of line dataset resampling function of the Supermap,we constructeda new calculation method of coastline tortuosity basing on Contour baseline. We extracted four basic data coastline from the year of 1990, 2000, 2007 and 2012 remote sensing images. Based on the results of coastlines tortuosity, by analysis of thetrends and variation characteristics nearly 20 years, we can obtain the following conclusions: it was an effective way to calculate coastline tortuosity by building contour baseline; continental coastline fluctuated trend, which can be divided intoascending, descending and fluctuations type; spatial distribution of Chinese continental coastline tortuosity have significant differences, on the whole northern tortuosity less than the South.