We show two effects of potential fluctuations(PF) on Coulomb Oscillati
on. The first one is the effect of series or parallel connection of tw
o dots with each one having PF. The second one is the effect of PF on
the Photon Assisted Tunneling(PAT). When PF takes a special configurat
ion, the dot pumped by microwave power becomes d.c. current source and
the current flow through particular discrete energy levels is reverse
d as the microwave power is increased.