In this paper are investigated abc—cubic graphs. The following theorems are obtained. Theorem 1 abe—cubic graphs without triangles exist iff triples (a
b
c) are the followings (1
1
1)
(1
1
2)
(1
1
3)
(1
2
2) (2
2
2). Theorem 2 Figure 12-1
Figure 13
Figure 14
Figure 15
and Figure 16 are the minimum graphs without triangles of 111—cubic
112—cubic
113—cubic
122—cubic and 222—cubic
respectively. Theorem 3 abc—cubic graphs exist iff triples (a
b
c) are the followings;:(1
1
1)
(1
1
2)
(1
1
3)
(1
1
4)
(1
1
5)
(1
2
2)
(1
2
3)
(1
2
4)
(1
3
3)
(2
2
2)
(2
2
3). Theorem 4 Figures from 23 to 33 are the minimum graphs of 111—cubic