In recent years, lake of Potamogeton crispus (yellow wheat grass) explosive reproduction caused a series of water quality problems. By studying the Luoma Lake Landsat 7 image at different time in 2012-2013,we can find that Landsat 7 imaging can accurately reflect the lakes Potamogeton crispus distribution; at the same time,Potamogeton crispus distribution is affected by many factors, especially human activities such as mining and aquatic breeding.