Industrial hemp fiber is a widely used natural fiber and it was planted widely in the world while the hemp stalk xylem is the byproduct of hemp fiber and it was not used well now.To use the hemp stalk fiber better,it studies the influence of varieties, gender and seeding-rate on the physical properties (MFA and the relative degree of crystallinity) of industrial hemp stalk fiber by Motic Images Plus 2.0 system and wide-angle X-ray diffraction (WXRD).The results showed that there was a great influence of varieties, gender and seeding-rate on the physical properties of hemp stalk fiber.The MFA and the relative degree of crystallinity in male plant of hemp stalk fiber are higher comparing with those in female plant of hemp stalk fiber when the seeding rate and the variety are the same.As the seeding rate increasing from 45/m2 to 105/m2, the MFA and the relative degree of crystallinity were increased either when the gender and the variety of hemp plant were the same.