BACKGROUND:　Fetal　electrocardiography　(FECG)　places　electrodes　on　the　maternal　abdomen　to　convert　the　fetal　electrocardiosignals　into　fetal　heart　rate　(FHR),　improving　the　accuracy　and　comfort　of　pregnant　woman.　At　the　same　time,　FECG　simplifies　the　procedure　of　long　term　monitoring　in　the　perinatal　period.　OBJECTIVE:　Investigating　the　influence　of　gestational　age　and　time　of　day　on　FHR　features　to　distinguish　between　non-stress　test　(NST)　normal　fetuses　and　NST　suspicious　fetuses.　METHODS:　A　novel　method　of　FHR　baseline　estimation　was　presented;　then　baseline　value　and　fetal　heart　rate　variation　(FHRV)　were　analyzed　in　the　time　domain　using　FHR　signals　recorded　from　52　fetuses.　RESULTS:　Baseline　values　in　1:　00,　2:　00,　4:　00,　5:　00　and　heart　rate　variation　(HRV)　distribution　showed　a　significant　difference　(p　＜　0.05)　between　NST　normal　fetuses　and　NST　suspicious　fetuses.　CONCLUSIONS:　The　results　suggest　that　NST　normal　and　suspicious　fetuses　had　same　outcome　and　different　FHR　features.　Accurately　distinguishing　normal　fetuses　and　suspicious　fetuses　is　important　for　lowering　the　false　positive　rate　and　reducing　unnecessary　clinical　intervention.