Abstract: V- type amylose- n- octyl octanol complex which B- type microcrystalline starch was made a combination with n- octyl octanol was prepared by means of heating reflux in the Et OH / H2 O system.Through single factor experiments,the effects of the starch / octanol ratio,the ethanol concentration,cooling crystallization conditions,insulation temperature and insulation time on the crystallinity of the V- type amylose- n- octyl octanol complex were investigated.Meanwhile,the X- ray diffraction was used to analyze the crystal structure of complex.The optimal technological condition was as follows: the starch / octanol ratio 10 ∶ 1,the ethanol concentration 35%,insulation temperature 80 ℃,insulation time 60 min and cooling crystallization conditions 5 ℃ / h.V- type amylose- n- octyl octanol complex was prepared under the condition,it was confirmed that the crystal structure of complex was V type,the crystallinity reached 61.29%.