China should continue to open up its economy, reform its exchange rate system and ease capital account controls, Zhou Xiaochuan, governor of the country's central bank, told Chinese business magazine Caijing in an interview. Zhou said the timing of reforms is very important and that the window of opportunity should be seized when it opens, according to the interview published on Monday. Costs will rise if the opportunity for reforms is missed, he said. His comments followed the first anniversary of the yuan's entry into the International Monetary Fund's basket of reserve currencies. China had hoped the inclusion of the yuan in the basket on Oct 1 last year would attract overseas investment and help stabilise the currency in the long run. The yuan has risen around 4 percent against the dollar so far this year.