Abstract: The paraffin method and the whole ovary stainclearing technique were used to study on polyembryony in Poa pratensis L. in WuLingShan .The results showed (1) that the multiple embryosacs in Ken tucky Bluegrass came from two ways which were from the megaspore mother cell and the nucellus cells,(2) that there were four sources about polyembryony in Poa pratensis L. which were from the fertilized egg, from the egg without fertilization, from the synergids and from nucellus cells.