The serum samples were obtained from the rnaternal and fetal pairs and various cancer patients. The serum levels of RNase inhibitor atd sialic acid were determined and the serum lipid were also separated by the thin-layer chromatography. folio wed by elution and colorimetric determination. The following results were obtained. 1) The serum RNase inhibitors in 12 maternal and fetal pairs showed 28±6% and 18±6% inhibition respectively. and the maternal level is higher than the fetal one with significance( P <0. 01) The maternal level is also higher than the control value of 16±4% with significance( P <0. 01) 2) The serum sialic acid contents of 10 maternal and fetal paire are 203±42mg/dl and 86±19mg/dl respectively. the matermal value showing 2.5 times higher than the total one. The sialic acid level of maternal serum is higher than 1.54±27mg/dl of the control value. but the fetal value is lower than the control one. 3) The TriglycerideCTG) level in maternal serum is 453±106mg/dl which is 6 times higher than the control value of 109±33mg/dl. The fetal value is lower than the control value. The free fatty acidCFFA) level in maternal serum is 17.9±5mg/dl. showing much higher than the fetal value of 4.5 ±llmg/dl.