Chromatography in native type V collagen from human placenta on phosphocellulose using nondenaturing conditions results in the partial resolution of two cellulose using nondenaturing conditions results in the partial resolution of two fractions. The first fraction contains each of the three type V alpha chains in approximately equal proportions and upon thermal denaturation exhibits a melting temperature of 33 degrees C. Fraction two contains the alpha 1 (V) and alpha 2 (V) chains in approximately a 2:1 ratio, respectively, and has a melting temperature of 35 degree C. These data indicate the presence of two molecular species of type V collagen in placenta, namely an alpha 1 (V) alpha 2 (V) alpha 3 (V) molecule and the previously described [alpha 1 (V)]2-alpha 2 (V) molecule.