The experimental set-up of time resolved, differential absorption used to mreasure the excited triplet absorption spectrum of dimerio chlorophyll α and the experimental results are reported. The peak absorption of the excited triplet of T1(4) and T1(D)are at 462nm and 466nrn,and the subsidiary maxima at 510 nm and 526 nm, respectively. The triplet lifetime of T1(A), T1(D), measured with a time-resolved double-beam method,is A/T=9.8+0.5,us and D/T=80+4us, respectively.