Objective To analyze CT ang MRI appearance of brain pilomyxoid astrocytomas (PMA). Methods The clinical history, pathological findings, CT and MRI appearance of three PMA patients were analyzed retrospectively. Combining literature review, the imaging feature of PMA were discussed. Results Three PMA were female children or adolescent, and the tumor located in the right thalamus, left temporal lobe/ basal ganglia and hypothalamic/chiasmatic region. One is soild and anothers are cystic, and all with intratumoral hemorrhage. On CT demonstrate as isodensity to mild hypodensity. On T1-Weighted imaging showed iso- to hypointense, and showed heterogeneous hyperintensity on T2WI. On DWI showed isointense or hyperintense and ADC value were increase. On contranst enhancement imaging the tumor showed heterogeneous enhancement or rim enhancement, perilesional edema were seen in two cases, another not. Conclusion Pilomyxoid astrocytoma is a recently identified invasion tumor type characteristically located in the hypothalamic/chiasmatic/third ventricular region and occurring in young children, with little difference imaging findings compared with PA. It is valuable for the diagnosis, therapy and prognosis study to recognition the imaging and pathology feature of PMA.