We Studied 48 patients(62 hips) who were performed hip arthroplasties at the Department of Orthopaedic Surgery, Soonchunhyang University hospital from February 1990 to August 1992. The purpose of the present study was to compare canal filling ratio and clinical results of cases treated by cementless femoral stem with 19 Harris Galante(straight stem), 23 Anatomic(curved stem) and 20 Multilock (straight stem). The follow-up periods ranged from 12 months to 36 months. We assessed canal filling at metaphysis, mid-stem and distal canal, and clinical results according to canal filling. The results were as follows ; 1. The average filling ratio of the medullary canal by each type of stem in the coronal plane were as follows. Harris Galante ; 80. 5%, Anatomic ; 79. 4%, Multilock; 79. 8% in metaphysis. Harris Galante ; 88. 7%, Anatomic ; 88. 3%, Multilock ; 87. 3% in mid-stem. Harris Galante ; 95. 1%, Anatomic 90. 2%, Multilock ; 94. 5% in distal canal. At distal canal, the average canal filling of Harris Galante and Multilock were more excellent than Anatomic in coronal plane. 2. The average filling ratio of the medullary canal by each type of stem in the saggital plane were as follows. Harris Galante ; 64. 0%, Anatomic 69. 6%, Multilock ; 68. 6% in metaphysis. Harris Galante ; 79. 6%, Anatomic; 84. 5%, Multilock; 80. 2 in mid-stem. Harris Galante ; 78. 3%, Anatomic ; 82. 6%, Multilock ; 84. 5% in distal canal. At mid-stem, the average canal filling of Anatomic was more excellent than Multilock and Harris Galante. At metaphysis and distal canal, the average canal filling of Anatomic and Multilock were more excellent than Harris Galante in saggital plane. 3. The average Harris's hip scores of each type of stem at the final follow-up was 89. 9 in Harris Galante, 90. 3 in Anatomic and 91. 9 points in Multilock. There was no significance statistically(p>0.05). 4. The correlation between the average canal filling and thigh pain was not statistically significant (p>0. 05).