To investigate the expression difference of microRNAs between the invasive and non-invasive pituitary adenomas and their association with the development of these two kinds of tumors,eight cases of non-functional pituitary adenoma (NFA) samples were selected to do the microarray assay (SHANGHAI BIOCHIP CO.,LTD).All of the samples were confirmed hormonal activity and cytodifferentiation by immunohistochemical examination,and according to the Knosps and Wilson-Handys classification criterion,4 cases were invasive adenomas while the others were non-invasive.