The present invention relates to a liquid formulation for parenteral administration comprising a somatostatin analogue or a pharmaceutically acceptable salt thereof and a buffer other than tartaric acid, process of preparation thereof and method of using the same. Particularly the present invention relates to liquid formulation for parenteral administration comprising pasireotide diaspartate and a buffer selected from citrate or phosphate-citrate, wherein the formulation has a pH of about 4 to about 4.5.