Depth sensing indentation (DSI) test at the range of 200-1800mN are performed on porous sialon ceramic to determine the indentation load on Young's modulus and hardness values. The young modulus and hardness (Dynamic and Martens) values are deduced by analysing the unloading segments of the DSI test load-displacement curve using the Oliver-Pharr method. It is found that Young's modulus E-r,E- the dynamic hardness H-D and the Martens hardness H-M exhibit significant indentation load dependences. The values of Young's modulus and hardness decrease with the increasing indentation load, as a result of indentation load effect. The experimental h(f)/h(m) ratios lower than the critical value 0.7, with h(m) being the maximum penetration depth during loading and h(f) the final unloading depth, indicate that our sample shows the work hardening behaviour.