Abstract: Because being paid close attention to environment impact from the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident, artificial radionuclides in the atmosphere, land and ocean were studied and monitored. The main nuclides detected are ¹³¹I, ¹³⁷Cs, ¹³⁴Cs and ¹²⁹I. When the concentration levels are measured, the transport path of radionuclides in the atmosphere and ocean were simulated. The results showed that controlling by climate condition, the airborne radionuclides released by FDNPP accident reached America via the Pacific, and then arrived to Europe over Atlantic, and finally transported to China. Over the globe the activity concentration of ¹³¹I from FDNPP accident is in the order of magnitude of mBq/m³, and 0.1-1 mBq/m³ for ¹³⁷Cs. The nuclides released to the sea headed eastward with the ocean current and then would circulate in the North Pacific. With mixing, the radionuclides went down to 200 m depth, where not very far from FDNPP. In the open ocean far from FDNPP, the ¹³⁷Cs activity concentration may be in the order of magnitude of 100 Bq/m³, but most of waters is in the Bq/m³ level, only slightly higher than background.