The DANSS detector will consist of highly segmented plastic scintillator with a total volume of 1 m3, surrounded with a composite shield of lead, copper and borated polyethylene, and vetoed against cosmic muons with a number of external scintillator plates. The basic element of DANSS is a polystyrene-based extruded scintillator strip (1×4×100 cm3) with a thin Gd-containing surface coating which is a light reflector and an (n,g )-converter simultaneously. The strip is read out with 3 wave length shifting fibers and SiPMs. In our study we investigated the response uniformity across the strip. The experiment installation was assembled from the two strips 100х30х5 mm running on the coincidence signals from the cosmic rays (trigger Counters). Studied strips 250х80х7 (with one fiber and with 3 fibers) was installed between them. Installation is able to move across the sample strip and provides 11 measurement points: 8 ones with a step of 5 mm and 3 ones atop the fiber. Number of events in each measurement is about 250. Relatively small statistics caused by a small sensitive area (5mm) of the trigger counters and difficulty of maintaining stable temperature indoors for a long time. Average number of SiPM pixels in the studied strip versus coordinates was measured. The results presented in the diagrams below. One photo-electron corresponds to about 1.2 pixels. The sum of the signals from the left and right fibers shows the uniformity which is sufficient for the DANSS goals. Conclusions The scintillator strip read out with 3 wave length shifting fibers and MPPC has been studied using cosmic particles. The uniformity of the response across the strip has been measured. It is sufficiently good for the DANSS experiment goals.