The biological synthesis pathways of salicylic acid (SA) include the shikimic acid pathway with phenylalanine as precursor and the isochorismate (IC) pathway, and the latter is the main pathway for SA synthesis. In bacteria, SA is generated directly from isochorismate under the enzymatic action of the IPL, which is not yet found in plants. The latest research proves that avrPphB susceptible 3 (PBS3) is the key factor in the conversion of IC into SA in plants, and reveals that the role of the enhanced disease susceptibility 5 (EDS5) as a transporter and the acyl transferase encoded by enhanced pseudomonas sensitiveity Ⅰcan act as an isochorismoyl-glutamate A pyruvoyl lyase in SA synthesis. This article reviews the latest research progress of SA synthesis pathway and its regulatory factors in plants, and further reveals its complex network and regulatory mechanism, so as to realize the comprehensive coordination between the timely induction of SA to plant resistance and the fine regulation of growth and development.