Abstract: The objective,the character of equipment and the analy- sis method of the petrophysics experirnent with nuclear mag- netic resonance(NMR)are introduced.Twenty-three core samples including siltstone and pelitic siltstone were ana- lyzed.Results show that the core analysis technology is ad- vantageous in porosity analysis,calculating permeability, fixing the cutoff value of T_2.The cutoff value of T_2 of move- able fluid in the measuring twenty-three samples is 6.46 16.8 ms with the mean value as 10.75 ms,which is obvious- ly different from the theoretical value 33 ms.The experi- mental results are utilized to apply in D block where reser- voirs are low in porosity and permeability,and a satisfying effect is obtained.