We survey the construction and properties of the Yamada polynomial of spatial graphs and present the Yamada polynomial formulae for some classes of graphs. Then we construct an infinite family of spatial graphs for which roots of Yamada polynomials are dense in the complex plane. It is well known due S. Kinoshita [14,15], that the Alexander ideal and Alexander polynomial are invariants of spatial graphs which are determined by the fundamental groups of the complements of spatial graphs.In 1989, S. Yamada [24] introduced Yamada polynomial of spatial graphs in R 3 . It is an concise and useful ambient isotopy invariant for graphs with maximal degree less than four. There are many interesting results on Yamada polynomial and its generalizations. J. Murakami [17] investigated the two-variable extension Z S of the Yamada polynomial and gave an invariant related to the HOMFLY polynomial. In 1994, the crossing number of spatial graphs in terms of the reduced degree of Yamada polynomial has been studied by T. Motohashi, Y. Ohyama and K. Taniyama [19]. In 1996, A. Dobrynin and A. Vesnin [7] studied properties of the Yamada polynomial of spatial graphs. For any graph G, V. Vershinin and A. Vesnin [23] defined bigraded cohomology groups whose graded Euler characteristic is a multiple of the Yamada polynomial of G. Another invariant of spatial graphs associated with U q (sl(2, C)) was introduced 2010 Mathematics Subject Classification. Primary 57M15; Secondary 05C31.