Various types of promising proton exchange membrane (PEM) are based on thermoplastics due to their excellent conductivity, good thermal and chemical stability, high durability as well as low fabrication and material cost. Sulfonated poly (ether ether ketone) or SPEEK is one of the examples of thermoplastic polymer that has been sulfonated to enhance its fundamental properties. These properties can be altered and improved through the fabrication process and modifications of the membranes. Thus, current researches on combining SPEEK with other polymers and inorganic particles through various fabrication methods are discussed in this review. The characterization of SPEEK-based membrane in terms of its water uptake, methanol permeability, proton conductivity, thermal and mechanical stability are also included in the discussion. The impact of membrane modifications on the fundamental properties and comparison of different membrane preparation methods are addressed. In addition, the advantages and drawbacks of modified membranes are summarized.