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Time-resolved fluorescence spectra of europium chelates have been recorded using the stroboscopic time resolution technique. These spectra show that the main emitting level $\mathrm{<mrow\; data-mjx-texclass="ORD">5</mrow>}D0$ of the europium ion is populated via the higher level $\mathrm{<mrow\; data-mjx-texclass="ORD">5</mrow>}D1$. The relaxation time of the level $\mathrm{<mrow\; data-mjx-texclass="ORD">5</mrow>}D1$ is measured to be of the order of $1-2\mu s$. The data indicate that the mechanism of relaxation in chelates is similar to that responsible for non-radiative quenching in these compounds. The time-resolved spectra may also give further support to Crosby's theory of energy transfer via the triplet state in chelates.