The present invention provides genes encoding novel luciferases having at least the properties of: being capable of using coelenterazine as their luminescent substrates; and being capable of being recombinantly expressed in a mammal cell as a host and produced to be secreted to the outside of the host cell. Specifically, the gene encoding novel luciferases according to the present invention is a DNA molecule comprising a nucleotide sequence encoding any of the full-length amino acid sequences of two types of luciferase proteins, luciferase 1 and luciferase 2, from M. pacifica, and is, for example, a gene encoding the following full-length amino acid sequence of the luciferase 1. MMEIQVLFAL ICFALVQANP TENKDDIDIV GVEGKFGTTD60 LETDLFTIVE DMNVISRDTN LANSDADRGK MPGKKLPLEV LIEMEANARK AGCTRGCLIC120 LSKIKCTAKM KVYIPGRCHD YGGDKKTGQA GIVGAIVDIP EISGFKELGP MEQFIAQVDL180 CADCTTGCLK GLANVKCSAL LKKWLPDRCA SFADKIQSEV DNIKGLAGDR210