Objective To present a miniaturized nucleic acid amplification system for spot rapid detection .Methods A miniaturized nucleic acid amplification system with structured packed porous media of particles to uniform the air temperature was designed according to the working principle and heat transfer characteristics of an air -heated nucleic acid amplification system.Thermodynamic simulation and temperature cycling test were carried on to verify the feasibility of the system.Results The structured packed porous media of particles worked well in uniforming the air temperature of the system and the temperature uniformity could reach 0.8℃.The miniaturized nucleic acid amplification system with a volume parameter of 80 mm ×40 mm ×20 mm(length ×height ×width)was portable.The average rate of heating was 10℃/s while the average rate of cooling was 5℃/s.Compared with standard PCR instrument , the miniaturized nucleic acid amplification system performed well in the process of amplification and met the requirements of preliminary design .Conclusion The miniaturized nucleic acid amplification system with a rapid reaction velocity and portable volume could be applied to nucleic acid detection of unknown samples on the spot .