Through analysis of the databank of Inspection America on field trials of genetic modified crops during the last 20 years, the basic rule and characteristics in research and development of genetic modified crops were studied. Data were processed with the software 'data perspective table' method imbedded in Microsoft Excel. Results showed that the field trials undertaken in America by the end of September 2008 totaled to 13782, involving 158 crops, ten categories of novel traits and about 98 companies or institutions. During 1987-2008, the number of field trials approved were firstly rising in a straight line, then stabilized at around 1 000 a year. The main test species included corn, soybean and cotton, accounting for 45.8%, 9.7%, 6.4%, respectively. The main characters were involved in the anti-herbicide, insect resistance and quality traits. About 62.7% field trials were undertaken by 5 private companies such as Monsanto and Pioneer Hi-Bred International, Inc. It is considered that the genetic modified crops which have a high economic value, mature technology and acceptable by consumers have broader prospects. China should continuously strengthen genetic modified research on non food crops.