Abstract: Because nontoxic nucleic acid dye Gelred has high cost, the minimum dosage of Gelred is investigated on non-denaturing polyacrylamide gel electrophoresis and agarose gel electrophoresis, without affecting the experimental results. 10000×Gelred was individually diluted to 1×, 10×, 20×, 30×, 40× and 50×, directly mixed with the PCR production of sugar beet, and then the mixture was directly detected by nondenaturing polyacrylamide gel electrophoresis and agarose gel electrophoresis. The detection was conducted with GEL imaging system. The other method was that the non-denaturing polyacrylamide gel and agarose gel were soaked in 1×Gelred and then showed by GEL imaging system. The results showed that 30×Gelred and above-30×Gelred were suitable for the detection of non-denaturing polyacrylamide gel electrophoresis and agarose gel electrophoresis, and 1×Gelred was more suitable for the soak of non-denaturing polyacrylamide gel. The dilute Gelred was mixed with PCR production, and then coordinated with non- denaturing polyacrylamide gel electrophoresis, which not only reduced the amount of Gelred, but also decreased the developing time.