A heated single pass spray chamber-based microscale flow injection sampling system was developed for the analysis of platinum in serum samples by inductively coupled plasma mass spectrometry.It consisted of a homemade demountable capillary microflow nebulizer，a single pass spray chamber heated by means of resistive heating，an eight channel sixteen port multifunctional injector valve and a syringe pump equipped with a 10 mL syringe as well as a peristaltic pump.Effects of the dimensions of spray chamber，the heating temperature and the sampling loop volume on the intensity were investigated.The maximum intensity were obtained with the single pass spray chamber with an inner diameter of 9 mm and a length of 6 cm for the heated section.When it was heated up to 90 ℃ and the sampling loop volume was selected to be 5 μL，the intensity of 195Pt was enhanced by a factor of 2.31 and the precision of transient signals for 195Pt was reduced from 5.1% to 2.2%,a signal peak with good configuration was obtained.Compared with the conventional sampling system，the heated single pass spray chamber-based microscale flow injection sampling system offers a little better sensitivity and detection limit in the case of lower sample consumption.The relative standard deviations of peak heights of 10 replicate trials of 10 μg/L standard solution and a serum sample were 2.9% and 3.3%，respectively.The contents of platinum in serum samples by the proposed method agreed well with those obtained by the conventional sampling system.The heated single pass spray chamber-based microscale flow injection sampling system can be applied in many fields，especially in the case of limited or rare samples.