1、磁性化合物的单晶生长及物理性能
2、新型拓扑半金属单晶及其输运性质
3、金属化合物的磁相变及其伴随效应，如磁热效应，磁致伸缩效应。

在国际学术期刊上发表SCI文章100多篇，其中第一作者和通讯作者文章40多篇， h因子26，文章被他人引用2000多次。
1. Z. P. Hou, W. J. Ren*, B. Ding, G. Z. Xu, Y. Wang, B. Yang, Q. Zhang, Y. Zhang, E. K. Liu, F. Xu, W. H. Wang*, G. H. Wu, X. X. Zhang, B. G. Shen, and Z. D. Zhang, “Observation of various and spontaneous magnetic skyrmionic Bubbles at room temperature in a frustrated kagome magnet with uniaxial magnetic anisotropy”, Adv. Mater. 29 (2017) 1701144.
2. W. J. Ren*, A. F. Wang, D. Graf, Y. Liu, Z. D. Zhang, W. G. Yin, and C. Petrovic, “Absence of Dirac states in BaZnBi2 induced by spin-orbit coupling”, Phys. Rev. B 97 (2018) 035147.
3. B. Li*, X. H. Luo, H. Wang, W. J. Ren*, S. Yano, C. W. Wang, J. S, Gardner, K. D. Liss, P. Miao, S. H. Li, T. Kamiyama, R.Q. Wu, Y. Kawakita, Z. D. Zhang, “Colossal negative thermal expansion induced by magnetic phase competition on frustrated lattices in Laves phase compound (Hf, Ta)Fe2”, Phys. Rev. B 93 (2016) 224405.
4. T. F. Duan, W. J. Ren*, W. L. Liu, S. J. Li, W. Liu, and Z. D. Zhang, “Magnetic anisotropy of single-crystalline Mn3Sn in triangular and helix-phase states”, Appl. Phys. Lett. 107 (2015) 082403.
5. W. J. Ren* and Z. D. Zhang*, “Progress in bulk MgCu2-type rare-earth iron magnetostrictive compounds”, Chin. Phys. B 22 (2013) 077507 (review).