The polarographic behaviour of acrolein in acetate-phosphate buffer solution has been investigated.Acrolein may give rise up to four polarographic waves in accordance with the pH of solution.These waves might probably be due to the existence of two different forms of acrolein,seemingly its monomer and dimer,in solution.By the addition of sodium bisulphite onto the aldehyde group and the conjugated double bond of acrolein,the reduction waves of acrolein disappeared,while that of formaldehyde still persisted in alkaline solution.In this way,the interference of acrolein on the determination of formaldehyde is eliminated.For the determination of acrolein and acetaldehyde,the buffer solution of pH 8.2 has been found to be suitable.A rapid method for the determination of formaldehyde,acrolein and acetaldehyde in admixtures has also been devised.