When people communicate, their messages convey affect alongside informational content. The affective dimension of messages is often unclear and open to multiple interpretations especially in an intercultural context. Thus, interlocutors may or may not achieve a state of affective grounding in which each person's affective behaviors are correctly interpreted by his/her partners. The current study examines the effects of culture on affective grounding. We conducted a laboratory experiment in which pairs of participants, half from America (A) and half from China (C), collaborated over instant messaging (IM). We found that affective grounding was harder to achieve for AA and AC pairs, but easier for CC pairs. We propose several design solutions to facilitate affective grounding in remote collaborations.