A procedure is described for the multifractal analysis of data on multiparticle production obtained at high energy either in experiment or in Monte Carlo simulation. It is shown how the spectrum $f(\ensuremath{\alpha})$ of the rapidity-density index $\ensuremath{\alpha}$ can be determined from the multiplicity fluctuation of the rapidity distribution, as the resolution is changed. The branching model is used to illustrate the procedure. It is found that the ${\ensuremath{\varphi}}^{3}$ model has a narrower $f(\ensuremath{\alpha})$ than the gluon model, suggesting that multifractality is a useful arena for confrontation between theory and experiment.