By comparing yeast genomes in three different periods,the variations of ORFs and genes for a recent years are given.The variations of short ORFs are instable. It is possible that the instability comes from the randomness of the DNA sequences. Simultaneously, some obvious characteristics of ORFs named with TY*(TY* ORFs) and ORFs named in other ways (* ORFs) are obtained and the suspicion that all the * ORFs do not exist in yeast genomes in 2001 and 2002 years is presented.