Objective: To establish a cDNA library of mouse dental germs. Method: First extraction of mRNA of mouse dental germs and synthesis of cDNA with reverse transcriptase were performed. The double strand cDNA library was titered and amplified with XL-1-blue as receptor bacterium and identified by polymerase chain reaction with 5 pairs of primer genes of mouse dental germ matrix proteins. Result: The titer of the unamplified library was 1.3 x 10⁶ pfu, and the percentage of recombinant clones was 72%. The 5 known genes were contained in the library, the size of the fragments were 670 bp to 1900 bp. Conclusion: This library is available, with a high titer, recombinant percentage, and large insert fragments of genes.