The purpose of this paper consisting to make clarify about the relations between the soil and the buckets excavative resistance force. This first report was made under the experimetal conditions as follows.
　Bucket capacity : 0.0625 m3 Soil : 4 kinds(sand with N value of 0 and 4, gravel and sand-graval mixture)
　Runningvelocity : 0.6～5.88m/min, Excavative depth : 10～ 40cm, Buckets revolution : 1～2rpm.
　This paper made a through investigation relating buckets excavative resistance force which have connection such factors as excavating center-sectional-area, circumference of the edge, excavating meandepth, excavating-length, running velocity and etc.
Within our tests, the followings were concluded,
1) The buckets excavative resistance force has a great influence on the excavating length.
2) The maximum excavative resistance force was recognized in case of mixed of sand and gravel.