Polymerase Chain Reaction (PCR)in recent years is a new disease detection methods basedon molecular biology level.It has the advantage of sensitive,specific,trace,simple,fast,but in the operation due to multiple factors,quality control is not easy to control.Especially in the first stage of quality control,it engages alot of operations and is weakest stage such needs most concern.It is necessary and important to have a good quality control;it not only improve the reliability and accu-racy of PCR testing,treatment of molecular biology,the professional level of work staff,but also reduce patient disputes and increase technology access,acceptance of the PCR laboratory.In this paper,the author from the factors which influence the first stage of PCR:whether correctly fill PCR test application form,patient preparation,handling,transportation,storage of good sample,unqualified specimen rejection,the requirement of laboratory technicians,calibration and maintenance on the in-struments;quality check on reagents,consumables quality inspection,standard operating procedures (SOP)writing,and la-boratory safety.Hope this paper can do a good reference for other same profession.