The invention provides an artificial
nucleic acid molecule which is used for improving the expression quantity of target
amino acid, polypeptide or
protein. The artificial
nucleic acid molecule at least comprises a target 5'
untranslated region (UTR), a target
coding region (CDS) and a target 3 '
untranslated region (UTR). Wherein the sequence of the target 5 'UTR is one of the following sequences: 5' UTR of a high-
expression gene and a 5 'UTR variant of the high-
expression gene. The sequence of the target 3 'UTR is one of the following sequences: 3' UTR of a high-
expression gene and a 3 'UTR variant of the high-expression
gene. Optionally, the artificial
nucleic acid molecule may further comprise, for example, a 5 '-end cap structure (Cap), a PolyA
tail. The 5 'UTR and the 3' UTR have regulating effects on translation and stability of nucleic acid molecules, so that the 5 'UTR, the 3' UTR and variants thereof are selected from high-expression genes, the nucleic acid molecules can be further stabilized and are not easy to degrade, and the amount of
protein or polypeptide obtained by translation of the nucleic acid molecules can be increased. The invention also provides methods for making, delivering, and using such artificial nucleic acid molecules, as well as the use of the artificial nucleic acid molecules for the treatment and / or prevention of related diseases or disorders.