Self-assessment with corrective training has been long seen crucial in helping learners improve their own work. This study investigates a group of 28 English-majored students' self-assessment of their Speaking performance at the end of a Speaking course at a university. First, the study explores their knowledge of the speaking test and then it provides them with 11 meetings of training on and practising using a speaking rubric which centres on the four grading criteria: Fluency and coherence, Pronunciation, Grammatical range, and Lexical resources. The participants' perception about their speaking performance after they took the speaking test is also explored. Finally, two examiners are employed to rate these students' speaking performance. The results revealed that the participants were found to be knowledgeable about the requirements in doing the test. Then, for their self-assessment on their test performance, they used the trained rubric to help them rate their work quite well, which highly correlated with the result of the teachers' rating which was also correlated with the average score of the two raters. The students' perceptions about their ability to perform these four Speaking grading criteria after taking the test also unveiled a strong connection to their overall self-assessment result.