The invention discloses a primer group for detecting polymorphism of a human cytochrome P450 related gene. The primer group comprises specific primers and probes aiming at gene sites of CYP2C19*2, CYP2C19*3, CYP3A4*18, CYP2C9*3, CYP2D6*10 and CYP3A5*3. The invention further relates to a kit for detecting polymorphism sites of the human cytochrome P450 related gene. The kit comprises PCR (Polymerase Chain Reaction) reaction liquid freeze-dried powder (PCR buffer, dNTPs, MgCl2, UNG enzyme, Taq enzyme and trehalose) with the primers and the probes. The invention further relates to a method for detecting polymorphism sites of the human cytochrome P450 related gene. By adopting the method, a DNA (Deoxyribonucleic Acid) extraction procedure is avoided, micro whole-blood amplification is directlyimplemented, a small amount of blood is used, and patients can be relieved from pain; the time and the labor can be saved, and in addition, economic expense can be greatly reduced.