Three-dimensional highly connected isonicotinic acid-base metal-organic frameworks (MOFs), [Co-6(II)(mu(3)-OH)(2)(in)(7)(HCOO)(3)H2O]center dot 4DMF (1) and [Mn-3(II)(mu(3)-OH)-(in)(3)(CH3COO)(2)] (2) (Hin = isonicotinic acid), have been successfully prepared. Compounds 1 and 2 were constructed from planar Co-6 cluster SBUs or rare 1D manganese-hydroxyl chain SBUs, respectively. Both SBUs contain triangular M-3(II)(OH) (M = Co and Mn) central units, which are connected by rare syn,anti,syn,anti- and syn,syn,anti-coordinated formic acid or acetic acid. Both compounds 1 and 2 have good thermal stability, while compound 2 also exhibits an extraordinarily high moisture stability. Magnetic studies demonstrate that 1 shows antiferromagnetic behavior, and 2 exhibits spin-canting antiferromagnetic ordering with soft-magnetic behavior.