WE DEFINE A SYSTEM OF IMPRIMITIVITY ON A Locally compact GROUPOID G, WHICH IS AN ORDERED TRIPLE Σ = (P, X, P) CONSISTING OF A REPRESENTATION P OF G ON A HILBERT BUNDLE H = (G0, {HU}, M), A G−SPACE X AND A H−PROJECTION-VALUED MEASURE P ON X WITH SOME SUITABLE PROPERTIES. THE AIM OF THIS PAPER IS TO SHOW THAT, WHEN Å = (P, X, P) IS A SYSTEM OF IMPRIMITIVITY ON A Locally compact GROUPOID G, THEN WE CAN DEFINE A REPRESENTATION FROM CC(X) TO B(L2(G0, {HU}, Μ)).