Rongsheng Petrochemical (SHE:002493) posted first-half attributable net profit of 5.11 billion yuan, up 749% from 602.1 million yuan the previous year.
Earnings per share jumped to 0.53 yuan from 0.06 yuan, according to a Tuesday filing with the Shenzhen bourse.
Operating revenue declined 13% year over year to 129.4 billion yuan from 148.6 billion yuan.
Shares of the petrochemical company were down 3% in recent trade.