In the rainy season, the climate fluctuation and rate of environmental change is very high. as well as the movement of clouds and water drops create a partial shaded situation on PV (photovoltaic) panel. Therefore, the extraction of maximum power from PV panel is the major challenge in the rainy season. This paper introduces a novel 'Improved Antlions Optimization' (IAO) algorithm for quick searching the maximum power point (MPP). The IAO algorithm is inspired to the hunting behavior of the antlion and the prey selection behavior of antlion is improved by using ranking technique. Therefore, IAO reaches the global maximum power point (GMPP) very quickly and suitable for online searching on hardware. Here, the IAO based GMPP tracking (GMPPT) algorithm on the five types of PV patterns, is tested in MATLAB simulation and verified on a developed hardware of the SPV system through comparison to the actual MPP. The satisfactory steady-state and dynamic performances of the IAO algorithm are demonstrated under variable irradiance and temperature during partial shaded conditions. © 2016 IEEE.