With ever-increasing operating frequencies and complicated artificial structures, loss effects become more and more important in applications of metamaterials. Based on circuit theory and transmission line principle, the design equations for effective electromagnetic (EM) parameters (attenuation constant α, phase constant β, characteristic impedance Z0) of general active and passive metamaterial are compared and derived from the equivalent lumped circuit parameters (R, G, L_L, C_L, L_R, C_R). To verify the design equations, theα, βand Z₀ indifferent cases, including balanced, unbalanced, lossless, passive and active, are shown by numerical simulations. The results show that using the active method can diminish the loss effects. Meantime, it also has influence on phase constant and real part of characteristic impedance.