Abstract: The preliminary studies were conducted to analyze the root microorganism ecology of two transgenic rice varleties(GMR)，which were genetically modified by the“rice chitinase gene(RC24)”．The results showed that the microorganism communities of the root and root surface in two GMR varieties were different from the non-transgenic variety．They had less numbers of endo-fungi．but their numbers of endo-bacteria were about 10 times more than the contro1．The root-ratios with endo-fungus in two GMR varieties were 55．2％ and 81．1％ ．while the control was 100％ ．Their species of bacteria and fungi in the root systems were also different from the control The root-ratios with VA mycorrhizic sac in GMR were lOW ．