Abstract: Objective To study the inhibitory effect of folate receptor-targeted MYCN gene siRNA on the expression and growth of LA-N-5 cells. Methods LA-N-5 cells were transfected with MYCN siRNA marked by folate receptor-targeted liposome-induced Cy3.The transfected siRNA was expressed as fluorescence intensity per μg protein.Changes in MYCN mRNA before and after transfection were detected by real-time quantitative PCR（RT-PCR）.Inhibition of LA-N-5 cell growth was assayed by MTT. Results Per μg protein contained（1 808.5±140.2）pg siRNA in LA-N-5 cells transfected with 100nmol/L MYCN siRNA.The inhibion rate of MYCN mRNA expression and LA-N-5 cell growth was 79.2% and 66.2%,respectively,72 hours after transfection. Conclusion Folate receptor-targeted liposome-induced MYCN siRNA can significantly inhibit the expression of MYCN mRNA in LA-N-5 cells and the growth of LA-N-5 cells in vitro,which may open up a new way to the gene and target therapy for neuroblastoma.