Objective: To investigate the spread direction and prognostic factors in limb-onset sporadic amyotrophic lateral sclerosis (sALS). Methods: Medical records of 128 patients with sALS were reviewed. Variables studied were age at symptom onset, gender, region and lateralization of onset, onset to diagnosis interval (ODI), progression direction, bulbar-involved, time from onset to bulbar-involved, ALSFRS-r, upper motor neuron (UMN) signs and progression rate. Results: First, the horizontal and vertical directions are major spreading directions in limb-onset sALS. Second, in crossed and interposed groups, while ODI is shorter, the progression rate is faster and UMN signs are more pronounced (p < 0.05). Third, ALSFRS-r, UMN signs and progression rate have significant differences between with-bulbar-involved and without-bulbar-involved (p < 0.05). The progression rate is related to the time from onset symptoms to bulbar-involved (correlation coefficient -0.535, p = 0.00). Fourth, in multivariate regression analysis, progression rate could respectively increase by about 1.14 and 3.89 times with shorter ODI and bulbar-involved in limb-onset sALS patients. Conclusions: The horizontal and vertical directions are the major spread directions in limb-onset sALS. Except for ALSFRS-r and ODI, bulbar-involved is an adverse factor for ALS progression, and progression rate is related to the time from onset symptoms to bulbar-involved.