Based on the SSM/I data from 1997 to 2016, the temporal and spatial variations of Arctic sea ice are studied from sea ice areas, sea ice margin zone and sea ice concentration. The results show that the sea ice areas for 20 years (1997–2016) are reduced at a speed of 0.0594 × 106 km2 per year, and the sea ice margin zone is reduced at a speed of 0.03 × 106 km2. From 1997 to 2006, the sea ice areas and margin zone show the same downward trend, which decreased by 0.062 × 106 km2 and 0.064 × 106 km2 per year, respectively. From 2007 to 2016, the sea ice areas and margin zone show an obvious fluctuation, which decreased by 0.027 × 106 km2 and 0.019 × 106 km2 per year, respectively. In the first ten years, the sea ice concentration (90–100%) is about 40%, and it is only about 20% in the second ten years, and the decrease is particularly obvious.