The present invention provides a toner for developing an electrostatic image which inhibits the filming of a wax on the development sleeve and photoreceptor to obtain a stable image. The present invention also provides a toner for developing an electrostatic image which provides a practically sufficiently wide fixing latitude. The present invention further provides an image formation process for forming a copied image with an excellent dot reproducibility, fine line reproducibility and gradation. A novel toner for developing an electrostatic image is provided, which comprises a particulate toner containing a polyolefin wax and a modified polyolefin wax, wherein the average diameter of wax particles dispersed in the particulate toner is not more than 0.5 .mu.m and the amount of wax exposed on the surface of said particulate toner is from 40 to 65% by weight. The particulate toner may comprise a finely divided magnetic powder in an amount of from 30 to 70% by weight. The content of modified polyolefin wax in the particulate toner is preferably greater than that of polyolefin wax.