Objective To synthetize a novel MR molecular imaging probe named USPIO?PEG?tLyP?1,and to evaluate its value in detecting U87 cells by MR imaging. Methods USPIO?PEG?tLyP?1 was synthetized by conjugating USPIO?PEG with tLyP?1. Neuropilin?1 expression levels of glioma cell lines were detected by Western blot. The cytotoxicity of USPIO?PEG and USPIO?PEG?tLyP?1 were assessed by MTT colorimetric assay. The uptake efficiency of USPIO?PEG?tLyP?1 was measured by Prussian blue staining, transmission electron microscope and MR imaging in vitro. Results The novel MR molecular imaging probe was synthetized with an average diameter of 43.84 nm. U87 glioma cell line was screened as test subject for the highly expression of NRP?1(P<0.05). USPIO?PEG?tLyP?1 group showed much more intracellular blue particles than USPIO?PEG group after Prussian blue staining. After incubation,USPIO?PEG?tLyP?1 mainly existed in lysosme,endoplasmic reticulum and mitochondria. In vitro MRI showed that USPIO?PEG?tLyP?1 significantly enhanced the negative contrast effect compared with USPIO?PEG(P<0.01). Conclusion The decoration of tLyP?1 enhanced targeting ability of USPIO?PEG to glioma cells and MR molecular imaging can be a promising method for early diagnosis of gliomas.