The data processing software system of Geostationary Ocean Color Imager (GOCI) is composed of the image preprocessing system (IMPS) and the GOCI data processing system (GDPS). IMPS generate GOCI level 1B from raw satellite data and GDPS is the post-processing system to generate GOCI level 2. IMPS have a radiometric correction module as IRCM and a geometric correction module named as INRSM. The former is focused on equipment's mechanical noise reduction and radiometric accuracy and the latter image navigation and image registration accuracy by landmark matching method and image mosaic method. GDPS have the atmospheric correction algorithms, as the spectral shape matching method (SSMM) and the sun glint correction algorithm (SGCA), and BRDF algorithm to solve bi-directional problem. Several Case-II water analytical algorithms, like chlorophyll concentration, suspended sediment and dissolved organic matter, are contained in GDPS. Also, GDPS will generate the value added product like water quality, fishery ground information, water current vector, etc. During in-orbit test period planned six months after successful launch of satellite, IMPS and GDPS will be verified with respect to those requirements and algorithms and functionality and accuracy by pre-defined test procedure like test, inspection, demonstration. And then those configuration parameters will be modified and the algorithm descriptions will be updated. In this paper, we will present the preliminary analyzed results of data processing system test and update planning during in-orbit test.