多変数複素解析，複素幾何を分野とする．中でも値分布理論（高次元ネヴァンリンナ理論），小林双曲的多様体，写像空間のモジュライ，及びそれ等の数論的アナロジーに興味を持って研究している．

1) J. Noguchi,　Holomorphic curves in algebraic varieties, Hiroshima Math. J. 7 (1977), 833-853.
2) J. Noguchi, Lemma on logarithmic derivatives and holomorphic curves in
algebraic varieties, Nagoya Math. J. 83 (1981), 213-233.
3) J. Noguchi, A higher dimensional analogue of Mordell's conjecture over function fields, Math. Ann. 258 (1981), 207-212.
4) J. Noguchi, Hyperbolic fibre spaces and Mordell's conjecture over function fields, Publ. RIMS, Kyoto Univ. 21 (1985), 27-46.
5) J. Noguchi, Moduli spaces of holomorphic mappings into hyperbolically imbedded complex spaces and locally symmetric spaces, Invent. Math. 93
(1988), 15-34.
6) J. Noguchi, Meromorphic mappings into compact hyperbolic complex spaces and geometric Diophantine problems, International J. Math. 3 (1992), 277-289.
7) K. Masuda and J. Noguchi, A construction of hyperbolic hypersurfaces of $\mathbf{P}^n (\mathbf{C})$, Math. Ann. 304 (1996), 339-362.
8) J. Noguchi, On holomorphic curves in semi-Abelian varieties, Math. Z. 228 (1998), 713-721.
9) Noguchi, J., Winkelmann, J. and Yamanoi, K., The second main theorem for holomorphic curves into semi-abelian varieties, Acta Math. 188 No. 1 (2002), 129-161.
10) Noguchi, J. and Winkelmann, J., Bounds for curves in abelian varieties, J.
reine angew. Math. 572 (2004), 27--47.
11) J. Noguchi, An arithmetic property of Shirosaki's hyperbolic projective
hypersurface, Forum Math. 15 (2003), 935--941.
12) Noguchi, J., Winkelmann, J. and Yamanoi, K., Degeneracy of holomorphic
curves into algebraic varieties, J. Math. Pures Appl. 88 Issue 3, (2007),

293--306.
13) Noguchi, J., Winkelmann, J. and Yamanoi, K., The second main theorem for holomorphic curves into semi-abelian varieties II, Forum Math. 20 (2008),

469--503.

1) 野口潤次郎（落合卓四郎と共著）, 幾何学的関数論, vii+223 pp., 岩波書店, 1984.
2) J. Noguchi and T. Ochiai, Geometric Function Theory in Several Complex
Variables, xi + 282 pp., Math. Monographs Vol. 80, Amer. Math. Soc., Providence.
3) 野口潤次郎, 複素解析概論, viii+307 pp., 裳華房, 1993.
4) J. Noguchi, Introduction to Complex Analysis, MMONO 168, xii+250 pp.,
Amer. Math. Soc., Rhode Island, 1997.
5) 野口潤次郎, 多変数ネヴァンリンナ理論とディオファントス近似, viii+264 pp.,

共立出版社, 2003.

Forum Mathematicum, Editor
J. Math. Analy. Appl., Associate Editor

Nagoya Mathematical Journal, Associate Editor

Fields Institute Workshop 2008, Organizer