Abstract： Objective： To discuss the effect of crocin on cell injury model of Parkinson disease and its possible mechanism. Methods：1-methyl-4-phenyl pyridinium cation(MPP + ) was acted on by different concentrations of crocin(10， 50 and 100μmol/L) to induce SK- N- SH cell. The contents of malondialdehyde(MDA) and reduced glutathione(GSH) in cells were detected by kits. Cell apoptosis was detected by flow cytometry. The expression levels of long non-coding RNA(lncRNA) testis- specific transcript Y- linked 15(TTTY15) and micro RNA(miRNA) let- 7c- 5p were detected by real time fluorescence quantitative PCR(RT-qPCR). The target relationship between TTTY15 and let-7c-5p was identified by dual luciferase reporter assay and RT- qPCR. TTTY15 small interfering RNA(si- TTTY15) and let- 7c- 5p mimics were transfected into human neuroblastoma cell(SK-N-SH) respectively；the effect of down-regulated TTTY15 or over-expression of let-7c-5p on SKN- SH cell injury induced by MPP+ was tested by the above methods. Results：Compared with those in the Con group，in the MPP + group， the MDA content in SK- N- SH cell was increased， and GSH content was significantly decreased(P＜0.05). Compared with those in the MPP+ group，in the MPP++crocin-L，MPP++crocin-M and MPP++crocin-H groups，the MDA contents in SK- N- SH cell were decreased， and GSH contents were increased(P＜0.05). In the MPP ++ crocin- L， MPP ++ crocin-M and MPP++crocin-H groups，the changes in MDA and GSH were associated with the dose of crocin；MDA was decreased as the dose was increased，and GSH was increased as the dose was increased(P＜0.05). Compared with those in the Con group，in the MPP+ group，the apoptosis rate of SK-N-SH cell and the expression of Bax protein were increased， and the expression of Bcl-2 protein was decreased(P＜0.05). Compared with those in the MPP+ group，in the MPP++crocin-L， MPP++crocin-M and MPP++crocin-H groups，the apoptosis rate of SK-N-SH cell and the expression of Bax protein were decreased，and the expression of Bcl-2 protein was increased(P＜0.05). When compared each detection index between the MPP++crocin-L，MPP++crocin-M and MPP++crocin-H groups，there was significance in the difference(P＜0.05). Compared with those in the Con group， in the MPP + group， the expression of TTTY15 of SK- N- SH cell was increased， and the expression of let-7c-5p was decreased(P＜0.05). Compared with those in the MPP+ group，in the MPP++crocin-L，MPP++ crocin-M and MPP++crocin-H groups，the expression of TTTY15 of SK-N-SH cell was decreased，and the expression of let-7c-5p was increased(P＜0.05). When compared each index between the MPP++crocin-L，MPP++crocin-M and MPP++ crocin- H groups， there was significance in the difference among the three groups(P＜0.05). Compared with that in the miR-NC group，in the let-7c-5p group，luciferase activity of SK-N-SH cell of WT-TTTY15 was decreased(P＜0.05)；when compared luciferase activity of SK- N- SH cell of MUT- TTTY15 between the two groups，there was no significance in the difference(P＞0.05). Compared with that in the pcDNA group，in the pcDNA-TTTY15 group，the expression of let-7c-5p of SK-N-SH cell was decreased(P＜0.05). Compared with that in the si-NC group，in the si-TTTY15 group，the expression of let- 7c- 5p of SK- N- SH cell was increased(P＜0.05). Compared with those in the MPP ++ si- NC group， in the MPP ++ si- TTTY15 group，the expression level of TTTY15 of SK-N-SH cell was decreased；the apoptosis rate，the expression of Bax protein and MDA content were decreased，and the expression of Bcl- 2 protein and GSH content were increased(P＜0.05). Compared with those in the MPP++NC group，in the MPP++let-7c-5p group，the expression level of let-7c-5p of SK-NSH cell was increased； the apoptosis rate， the expression of Bax protein and MDA content were decreased， and the expression of Bcl-2 protein and GSH content were increased(P＜0.05). Conclusion：Crocin has protective effect on cell injury model of Parkinson disease，whose mechanism may be related to down-regulation of lncRNA TTTY15/let-7c-5p pathway.