The natural morphological growth and invasion of World Health Organization (WHO) grade II glioma has not been well documented in previous literature. This study retrospectively analysed the morphological invasive characteristics of adult. Data from 20 patients (15 men, 5 women; mean age, 38 years; age range, 22-64 years), who had supratentorial WHO grade II gliomas and consecutively underwent serial preoperative conventional MR examinations were retrospectively analysed, for change in location, and evidence of haemorrhage, enhancement, necrosis, peri-tumoural oedema and mass effect. Seven tumours, initially located in the grey matter (3, insula; 4, frontal cortices), expanded without definite invasion along fibres. Thirteen tumours, originated from the junction of grey and white matter, invaded in different orientations (4, contralateral invasion; 1, ipsilateral remote dissemination; 8, ipsilateral invasion via the surrounding fibres). The increased proportion of haemorrhage, enhancement, necrosis, peri-tumoural oedema and mass effect in the first and last pre-operative examinations were 14% (1/7), 29% (2/7), 43% (3/7), 43% (3/7) and 29% (2/7), respectively, for the 7 tumours initially located in grey matter, and 15% (2/13), 38% (5/13), 31% (4/13), 15% (2/13) and 38% (5/13) respectively for the 13 tumours initially located at the junction of grey and white matter. The growth of supratentorial WHO grade II glioma is a complicated process. The growth directionality may be determined by initial tumour location.