Abstract: Alpha-silicon nitride whiskers and crystalline pillars were produced by amorphous silicon nitride ultrafine powders.The study includes the effect of growth temperature on the defect of whiskers.The results show that the integrity of obtained crystal has related to the growth temperature when whiskers are growing.The relatively integral crystal can only be obtained in a certain range of temperature(1430℃±30 ℃).The growth temperature too high or too low may cause imperfection of the growing crystal and the whiskers with many defects.If the temperature continues to go up,crystalline grain will appear in the whiskers which will become crystalline pillar afterwards.