The proposed online supporting system consists of two major parts. The first part constitutes a corpus of graded ELPA writing (henceforth the ELPA corpus) and a corpus of English academic writing (henceforth the EAP corpus) by HKIED students, while the second will be  developed based on the feedback supplied by an online automatic e-rater for writing from an external service provider, i.e. Pigai.  Lexical, grammatical, syntactical and discourse analyses of both corpora will be carried out.