The present invention relates to a component and method used for cMLCK gene introduction. Provided are a component and method for treating severe heart failure via cMLCK gene introduction. Specifically, an effective dose of a polynucleotide vector which encodes the cMLCK protein is applied to an individual so as to improve the ventricular function of the heart, said polynucleotide vector encoding the cMLCK protein in heart cells of the individual. Also provided are a component and method for expressing the cMLCK protein in an individual. Specifically, a polynucleotide vector capable of encoding the cMLCK protein is applied to an individual, said vector being capable of expressing the cMLCK protein in heart cells of the individual, said individual suffering from severe heart failure.
