Some pseudogenes have been reported to play important roles in gene regulation,but little is known about the evolutionary direction of pseudogenes at population level as well as the possible relationship between pseudogene functions and evolutionary process ofpseudogenes.In this study,we characterized human processed pseudogenes in terms of evolutionary dynamics.Our results show that pseudogenes tend to evolve toward: lower GC content,strong dinucleotide bias,reduced abundance of transcription factor binding motifs and short palindromes,and decreased ability to form nucleosomes.