Thirty-three globular clusters of our Galaxy were observed with the filters of the Vilnius photometric system UPXYZVS with 3450, 3740, 4050, 4660, 5160, 5440, 6550 å filters (Straižys 1977). For the classification of clusters in metallicities the reddening-free parameters QUYV QPYV and QXYV can be used. In Figure 1 these Q parameters, having a range of variation of the order of 0.4, are plotted against metallicity values from Kukarkin (1974). The parameter QPYZ has an even larger range of variation (of the order of 0.6). For determination of color excesses of clusters every color index can be used if its intrinsic values for a given metallicity defined by quantities Q are known (Figure 2). Average color excesses determined from the diagrams QUYV, (Y-V)o; QPYV, (Y-V)o and QXYV (Y-V)o and transformed to EB-V in Figure 3 are compared with color excesses from Kukarkin (1974). To summarize, the Vilnius system presents a number of metallicity sensitive, reddening-free parameters which can be used for [Fe/H] and color-excess determinations of globular clusters.