We report the anomalous superconductivity found in bismuthates with different compositions. In the Sr 1− x K x BiO 3 (SKBO) compound the field-induced superconductivity is observed, which shows a striking suppression of the reentrant resistance at T< T c by applying an external magnetic field ( H) or increasing the electrical transport current ( I). The magnetotransport measurements on several different samples reveal that the reentrant resistance behavior with H and I is related to the normal state transport properties. Disordered junction barriers between superconducting grains seem to be important for the observed anomalous reentrant resistance phenomena. In the Ba 1− x K x BiO 3 system, the whole region of the superconducting cubic phase diagram from x=0.4 up to x=1 was investigated for the first time by using the high pressure and high temperature synthesis technique. The superconducting temperature ( T c) of Ba 1− x K x BiO 3 (BKBO) samples shows a parabolic decrease of T c from the well-known Ba 0.63K 0.37BiO 3 composition with T c=30.4 K to Ba 0.24K 0.76BiO 3 with very low diamagnetic signal at nearly 3 K. However, we found that further increasing x gives an increase of T c up to 9 K for x=1. Possible physical origins of the field-induced superconductivity in SKBO and the anomalous superconducting region in high potassium concentration ( x>0.8) BKBO are discussed.