This paper deals with a layout problem of trees satisfying certain given aesthetic conditions. It is known as tidy drawing problems of trees . We consider a type of tree called a tree-structured diagram in which each node has variable size and location.In this paper, for drawing tree-type program flowcharts, we first formulate tidy drawing problems of tree-structured diagrams on the integral lattice. The formulation defines a tree-structured diagram and aesthetic conditions, which are modifications of the tidy drawing problem of trees. Second, we develop O(n)- and O(n 2 )-time algorithms to provide layouts which satisfy the conditions introduced. As a result, we obtain the relationship between the aesthetic conditions and the time complexity of algorithms.