In this paper, a combined experimental and quasi-linear simulation study of ion-scale turbulence and transport is presented in the core of electron cyclotron resonance heating (ECRH) modulated H mode plasma on Experimental-Advanced-Superconducting-Tokamak (EAST). By taking experimentally measured plasma profiles as simulation input, employment of linear IFS/PPPL and Peeters model suggested that two plasma profile platforms were formed just beside the trapped electron mode (TEM) stability boundary under on-axis ECRH modulation at mid-radius region (). To further quantify their growth rates, wavenumber range and transport characteristics, local quasi-linear analysis is performed at two radial positions (ρ = 0.35 and ρ = 0.45) using the trapped gyro-Landau fluid (TGLF) code. The simulation results at ρ = 0.35 and ρ = 0.45 later show consistent agreement with the experimentally observed turbulence characteristics via ion-scale cm−1 X-mode density fluctuation microwave reflectometer , and the simulated quasi-linear transport properties suggested a possible explanation for the overall confinement improvement and local heat flux reduction calculated by the TRANSP code. Parameter scans further reveal that the driving sources for TEM turbulence were different across the plasma core region and through out the modulation period. A possible driving source transition of TEM at ρ = 0.45 from temperature gradient (TGTEM) to density gradient (DGTEM) induced by ECRH modulation was suggested by TGLF results. Distinct difference of transport capabilities in electron particle and heat transport has been found between TGTEM and DGTEM. These results demonstrate for the first time of the transition from TGTEM to DGTEM and their transport capabilities in EAST core region, implying the importance of TEM activities in future electron-heating-dominated devices.