Recent observations on both microquasars and AGNs with radio and X‐ray telescopes have revealed remarkable radio/X‐ray correlation of these objects. Because the radio and X‐ray emissions are mainly emitted from jet and accretion flow, the radio/X‐ray correlation can be used to probe the accretion‐jet physics in these accreting black hole systems. Using a uniform broad line SDSS AGN sample, we derived the black hole fundamental plane relationship among the 1.4 GHz radio luminosity (Lr), 0.1–2.4 keV X‐ray luminosity (LX), and black hole mass (M). We found from our sample that the fundamental plane relation has a very weak dependence on the black hole mass, and a tight correlation also exists between the Eddington luminosity scaled X‐ray and radio luminosities for the radio quiet subsample. In addition, we noticed that radio‐loud AGNs have steeper power‐law slope in the radio/X‐ray correlation than radio‐quiet AGNs. This is mainly due to the different origin of X‐ray emissions in radio‐loud and radio‐quiet A...