In this paper, we propose VATL(Voltage-controlled Artificial Transmission Line) employing periodically loaded diodes for application to on-chip matching components on MMIC. Compared with conventional microstrip line, the VATL showed a much shorter wave length due to periodic capacitance of diodes, and the characteristic impedance of the VATL was easily controlled bγ changing supplied voltage. Concretely, the characteristic impedance of the VATL was changed from $80{sim}20{Omega}$ in a range of $0{sim}1.05V$ and the VATL showed a wavelength of 1.5mm at 20GHz, while conventional microstrip line showed a wavelength of 5.3mm at the same frequency. Using the VATL, a ${lambda}/4$ impedance transformer was fabricated on GaAs MMIC for application to on-chip matching components on MMIC. Using the ${lambda}/4$ impedance transformer made it possible to perform impedance matching between RF components with various characteristic impedance of $30{sim}100{Omega}$ by adjusting applied Voltage