In our attempt to develop effective EGFR-TKIs, two series of 1H-pyrazolo[3,4-d]pyrimidine derivatives were designed and synthesized. All the newly synthesized compounds were evaluated in vitro for their inhibitory activities against EGFR(WT). Compounds 15(b), 15(j), and 18(d) potently inhibited EGFR(WT) at sub-micro molar IC50 values comparable to that of erlotinib. Moreover, thirteen compounds that showed promising IC50 values against EGFR(WT) were tested in vitro for their inhibitory activities against mutant EGFR(T790m). Compounds 17(d) and 17(f), exhibited potent inhibitory activities towards EGFR(T790M) comparable to osimertinib. Compounds that showed promising IC50 values against EGFR(WT) were further tested for their anti-proliferative activities against three cancer cell lines bearing EGFR(WT)(MCF-7, HepG2, A549), and two cancer cell lines bearing EGFR(T79OM )(H1975 and HCC827). Compounds 15(g), 15(j),15(n), 18(d) and 18(e) were the most potent anticancer agents against the EGFR(WT) containing cells, while compounds 15(e), 17(d) and 17(f) showed promising anti-proliferative activities against EGFR(T79OM )containing cells. Furthermore, the most active compound 18(d) was selected for further studies regarding to its effects on cell cycle progression and induction of apoptosis in the HepG2 cell line. The results indicated that this compound is good apoptotic agent and arrests G(0)/G(l) and G(2)/M phases of cell cycle. Finally, molecular docking studies were performed to investigate binding pattern of the synthesized compounds with the prospective targets, EGFR(WT)(PDB: 4HJO) and EGFR(T79OM)(PDB: 3W2O).