Abstract: This invention relates to oral pharmaceutical compositions of metformin and rosuvastatin. In detail, a pharmaceutical composition comprising metformin, rosuvastatin, sustained release carriers and/or excipients reduces the side effects caused by statins and enhances safety, patients' convenience and compliance with its one-per-day dosage. In addition, regulation of an early effective blood concentration of the drug and maintenance of the drug's concentration at a steady level in vivo by a controlled-release can be advantageously used as a pharmaceutical composition for preventing and treating hyperlipidemia.