The effective pressure law (EPL), Peff = Pc - α Pf, where Peff denotes the effective pressure, Pc the confining pressure, Pf the pore fluid pressure and α the effective pressure coefficient, has been proved to be very useful in describing the effect of pore fluid pressure on rock properties. The coefficient α can be a constant (linear EPL) or, as has been previously reported for tight sandstones, a function of Pc and Pf (non-linear EPL). Besides, the coefficient α is different for different rock properties, such as permeability and deformation which are two most important properties for completion and production activities. Here, the permeability and deformation of tight sandstone from Chinese gas reservoir were measured at the same time while cycling Pf and Pc according to two different procedures. In the first place, Pf and Pc were varied simultaneously so as to keep the pressure difference, Pc - Pf, constant. Three cycles, each with a distinct value of Pc - Pf were performed. In the second procedure, we cycled the pore pressure between a value and one slightly lower than Pc, while keeping the confining pressure constant. Again, three cycles with fixed values of Pc were performed. We used Argon gas to minimize chemical effects. The results showed that under constant Pc, the permeability decreased with the decrease of Pf but the deformation decrease with the increase of Pf, which agreed with previous results. Under constant Pc - Pf, the permeability decrease with the increase of Pf but the deformation decrease with the increase of Pf. The permeability or deformation was not constant although the value of Pc - Pf was constant, indicating that the permeability or deformation of our tight sandstone was not controlled by the ordinary effective pressure law. We estimated the EPL coefficient αk for permeability and αɛ for deformation using the method proposed by Xiao et al.[2017]. We found that the EPL coefficients αk and αɛ appeared to be a well-defined decreasing function of Terzaghi's differential pressure α(pc - pf); the range[0.633, 1.015] of coefficients αk was greater than the one [0.595, 0.724] of αɛ . Improving the accuracy of the EPL will provide a more realistic determination and prediction of the permeability or deformation of tight sandstones under varying loading conditions.