The Middle Childhood Attachment Micro-Observation System (MCAM) has been developed to micro-code attachment-related behaviors of a parent and a child (aged 8 - 12). The current version has been used by Bodner et al. (2019). In this study, a mother and child were asked to solve a unsolvable puzzle. After an initial stress induction to the child the mother joins the child. This interaction is videotaped and coded in two second intervals with the present MCAM coding scheme. The MCAM system captures proximity-seeking behaviors as well as cooperative problem-solving behaviors. The subcategories are inspired by the Emotional Availability Scales, middle childhood version (EAS) (Biringen, 2000; Biringen et al., 1998) and the strange situation procedure (Ainsworth et al., 1978), but adapted to the micro-coding purpose (i.e., indicating the presence or absence of each code for small time intervals) by including detailed descriptions to help to detect the behavior in small intervals. The result of the coding is a multivariate binary time series.