Sonoporation has been shown to have an important role in biotechnology for gene therapy and drug delivery. This pa per presents a novel microfluidic sonoporation system that achieves high rates of cell transfection and cell viability by operating the sonoporation chamber at resonance. The paper presents a the oretical analysis of the resonant sonoporation chamber design, which achieves sonoporation by forming an ultrasonic standing wave across the chamber. A piezoelectric transducer (PZT 26) is used to generate the ultrasound and the different material thick nesses have been identified to give a chamber resonance at 980 kHz. The efficiency of the sonoporation system was determined exper imentally under a range of sonoporation conditions and different exposures time (5,10,15, and 20 s, respectively) using HeLa cells and plasmid (peGFP-Nl). The experimental results achieve a cell transfection efficiency of 68.9% (analysis of variance, ANOVA,p <; 0.05) at the resonant frequency of 980 kHz at 100 Vp-p (19.5 MPa) with a cell viability of 77% after 10 s of insonication.