Shape factor control is important in chemically produced toners (CPT) to achieve higher toner transfer efficiency in the machine and better image quality. Among all the CPT processes, emulsion aggregation process offers more tunability on particle design, especially on particle composition, structure, and morphology and shape factor. The coalescing agents have been widely used in painting/coating industrial applications to increase the easiness of latex particles to coalescence through softening the latex particles and lowering the minimum film-formation temperature (MFFT) of the latex.In this paper, criteria of good coalescence agent in CPT particle shape control will be discussed. Examples of non-reactive and reactive coalescence agents will be provided. Their effects on the toner particle shape factors control will be discussed in emulsion aggregation process.