To provide a method for cell-free protein synthesis having high practicality and capable of forming a large synthetic amount of proteins by a simple and low-cost method.

The cell-free protein synthesis is carried out in a reaction liquid containing mRNA and an extracted liquid derived from live cell, wherein the reaction liquid contains an oligonucleotide complementary to a sequence existing in the 3'-terminal region of the mRNA. Preferably, the oligonucleotide fragment is selected from DNA, DNA analog, RNA and RNA analog, and the live cell is an insect cell.