Downs syndrome prenatal screening has developed vigorously in China since 2000.According to the official figures, more than 17 million pregnant women has accepted Downs syndrome prenatal screening in2009, accounts for 12.54％ of total cases.The biggest obstacle of keep on introducing the screening to rural area is the inconvenieneeon transportationof serum samples.So we try to find an effective and easy way to achieve long distance screening sample transportation and detection.That is dried bloods spots screeningtechnique (DBS).