Set for Sunday, the referendum follows some of bloodiest fighting seen during the crisis, with 30 pro-Russian separatists and four Ukrainian soldiers reported to have been killed in the last week.
The referendum question to be put to voters is: "Do you support the act of proclamation of independent sovereignty for the Donetsk People's Republic?''
The Ukrainian government has said it will ignore the results of the referendum. Investors also took heart from a better than expected inflation report from China.
Consumer prices in the world's second largest economy rose 1.8 per cent in April from the previous year, with producer prices dropping two per cent.
Asian shares were also boosted by rebounds for Galaxy Entertainment Group and Canon of 5.5 and 2.6 per cent respectively.