Two new (1 and 3) and two known diarylheptanoids (2 and 4), along with two tetralones (5 and 6), one naphthoquinone (7), four phenylpropanoids (8-11), and one phenol (12) were isolated from the leaves of Juglans mandshurica. Their structures were elucidated on the basis of spectral and chemical data. Compounds 2 and 10 are firstly isolated from this plant and 8 and 12 were isolated from the Juglans genus for the first time. Among these compounds, only 7 exhibited moderate cytotoxicities against cultured MGC-803, A549, K562, and HeLa tumor cell lines with IC50 values of 25.90, 28.60, 39.06, 44.90 μM, respectively.