Winter wheat seedtime is important for wheat growth. It affects the wheat yield and quality. The objective of this study is monitoring the winter wheat seedtime through remote sensing imagery. Two HJ-1B images and one Landsat5 TM image were used in this study. Three Vegetation Indices, DVI, SAVI and RDVI were calculated. The correlation about the wheat seedtime and VIs were analyzed. The result indicated that wheat growth was negatively correlated with seedtime. Wheat VIs during 40-60 days after sowing is best for seedtime monitoring. The correlation coefficient for DVI of November 22th HJ-1B and seedtime reached -0.51. The seedtime for whole wheat plant field of Beijing area was inverted through the model. The results show that area for seeded before Sept 30th was about 12.7 thousands ha, 31. 8 thousands ha between Oct 1th and Oct 8th, and 16.2 thousands ha seeded after Oct 8th during 2009-2010 year.