Background Motor disorders are part of the clinical phenotype of Autism Spectrum Disorders (ASDs) (Gowen & Hamilton, 2013) even if they are not taken yet as diagnostic criteria. They can involve both fine (Ming et al., 2007) and gross motor skills (Calhoun et al., 2011). Motor anticipation (MA) is a characteristic of motor control that is disturbed in ASDs and has a negative impact on gross motor skills (Fournier et al., 2010) and fine motor skills (Schmitz et al., 2003). Now, studies of motor abnormalities in ASD have focused on fine or gross motor skills separately. Given the heterogeneity of autistic clinical symptomatology, we can assume the existence of a spectrum of deficits including the two types of motor skills. MA is involved in all daily motor activities and a limitation at this level in turn limits the functional independence in everyday life of people with ASD (Jasmin et al., 2009). Objective We study motor control in ASDs throw a gross and fine motor task. Methods Population: twenty-seven participants with ASD (9 girls) and typically developing (TD) children (14 girls) matched pairs on age (TD = 8,42 years, TSA = 8,75 years), and nonverbal IQ (Scaled score: Ss-TSA= 11; Ss-TD = 12) performed both a handwriting task (HT) and a gait initiation task (GIT) respectively in fine and gross motricity. Protocol: In the GIT, children stood with each foot on a force plate (sampled at 1000 Hz). After 3s of standing still, they were asked to walk in front of them (5 times). Ground Reaction Forces were recorded using adjacent force plates. A Vicon 3D motion-capture system with 18 cameras sampled at 100 Hz recorded the trajectories of 34 reflective markers placed on anatomical landmarks. The HT was performed on a graphics tablet and involves reproducing two digraphs (ll & ln, 10cm height each), ten times. The statistical analyses focused on the first L. Analysis: Analyses performed in the GIT concerned anticipated postural adjustments (APAs) which occurs prior to the onset of the voluntary movement in order to encourage movement and performance in the task ahead. The margin of stability (MoS, Hof, 2008) was study at foot-off (Figure 1). In HT, the analyses focused on SPARC (Spectral ARC Length, Balasubramanian et al., 2015) of the 1st L. Results 1/ During the GIT, at foot-off, ASD childrens’ MoS is significantly greater than TDs in the mediolateral axis (ML). 2/ During the HT, ASDs children have a SPARC significantly more pronounced than TDs ones in each digraph. Discussion Result 1/ indicates that, when ASDs children start walking, they are more unbalanced on the ML axis than TDs. Result 2/ indicates that, whatever the digrams, children's motor control leads them to produce a less fluid movement. Conclusions Because cerebellum is implied in signalling the sensory discrepancy between feedforward and feedback consequences of movements, it is involved in motor anticipation. These results are in line with the cerebellar dysfunction theory in ASDs (Mosconi et al., 2015) and are discussed in accordance with it.