In 1867，legal aid became part of the national responsibility through the adoption of a piece of legislation and it makes UK the first country in the world that establishing legal aid system. A series of legislations afterwards expanded the scope of legal aid，expanding from the trial stage to the investigation stage，from specific kind of cases to all kinds of criminal cases. However，the legal aid system in UK also faces some problems，e.g. sufficient legal aid lawyers，budgets cut in legal aid service etc. China faces the same situation as well. Therefore，the experience and lessons from UK could benefit the Chinese counterpart to some extent.