The idea of difference sequence spaces was introduced by Kizmaz [6], and this concept was generalized by Bektas and Colak [1]. In this paper, we define the sequence spaces <img border=0 width=99 height=23 src="http:/fbpe/img/proy/v29n1/img01.JPG" alt="http:/fbpe/img/proy/v29n1/img01.JPG">and <img border=0 width=99 height=23 src="http:/fbpe/img/proy/v29n1/img02.JPG" alt="http:/fbpe/img/proy/v29n1/img02.JPG">, where F = (f k) is a sequence of modulus functions, and examine some inclusion relations and properties of these spaces.