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<p>Although great progress has been made in estimating surface solar radiation (<span class="inline-formula"><i>R</i>_s</span>) from meteorological observations, satellite retrieval, and reanalysis, getting best-estimated long-term variations in <span class="inline-formula"><i>R</i>_s</span> are sorely needed for climate studies. It has been shown that <span class="inline-formula"><i>R</i>_s</span> data derived from sunshine duration (SunDu) can provide reliable long-term variability, but such data are available at sparsely distributed weather stations. Here, we merge SunDu-derived <span class="inline-formula"><i>R</i>_s</span> with satellite-derived cloud fraction and aerosol optical depth (AOD) to generate high-spatial-resolution (0.1<span class="inline-formula">^∘</span>) <span class="inline-formula"><i>R</i>_s</span> over China from 2000 to 2017. The geographically weighted regression (GWR) and ordinary least-squares regression (OLS) merging methods are compared, and GWR is found to perform better. Based on the SunDu-derived <span class="inline-formula"><i>R</i>_s</span> from 97 meteorological observation stations, which are co-located with those that direct <span class="inline-formula"><i>R</i>_s</span> measurement sites, the GWR incorporated with satellite cloud fraction and AOD data produces monthly <span class="inline-formula"><i>R</i>_s</span> with <span class="inline-formula"><i>R</i>²=0.97</span> and standard deviation <span class="inline-formula">=11.14</span> <span class="inline-formula">W m⁻²</span>, while GWR driven by only cloud fraction produces similar results with <span class="inline-formula"><i>R</i>²=0.97</span> and standard deviation <span class="inline-formula">=11.41</span> <span class="inline-formula">W m⁻²</span>. This similarity is because SunDu-derived <span class="inline-formula"><i>R</i>_s</span> has included the impact of aerosols. This finding can help to build long-term <span class="inline-formula"><i>R</i>_s</span> variations based on cloud data, such as Advanced Very High Resolution Radiometer (AVHRR) cloud retrievals, especially before 2000, when satellite AOD retrievals are not unavailable. The merged <span class="inline-formula"><i>R</i>_s</span> product at a spatial resolution of 0.1<span class="inline-formula">^∘</span> in this study can be downloaded at <a href="https://doi.org/10.1594/PANGAEA.921847">https://doi.org/10.1594/PANGAEA.921847</a> (Feng and Wang, 2020).</p>