The present paper reports a novel chemiluminescence (CL) system

iso-propylalcohol-ClO

-

-H

2

O

2

. In basic medium

iso-propylalcohol can react with ClO

-

or H

2

O

2

to produce CL emission. If iso-propylalcohol was initially mixed with ClO

-

and then H

2

O

2

was added to the above mixed solution the CL intensity became greater. The kinetic process agreed with the index attenuation formula

I(t)

=16exp(-0.21

t

)

and the constant of attenuation speed was 0.21sec

-1

. The effects of reagent concentration

some metal ions and pH value of ClO

-

solution on the CL in tensity were studied. Acetaldehyde can enhance the CL intensity

and the enhanced CL intensity is proportional to the concentration of acetal-dehyed within the range of 5.0×10

-10

g/ml-1.0×10

-6

g/ml. Based on this result

we have developed a new CL method for the determination of trace acetaldehyde

with which some foreign inorganic ions as well as usual organic compounds do not interfere. The mechanism of the CL reaction has also been briefly discussed.