Effective use of grammar to inform news or events through social media needs to be applied. However, in practice there are still several accounts on social media, like Instagram, that upload information or news using ineffective grammar. One example of this problem is in the Instagram Info Cegatan Solo (ICS/Solo Stopping Area Info) upload. Therefore, this study of ineffectiveness of captions uploded on Instagram at ICS intended to analyze and determine the forms of ineffectiveness of the sentences uploaded. This research is classified as a qualitative descriptive study using the method of note and note technique. The data of this study were the captions of ICS uploads on Instagram in March 2020 which were then analyzed by using qualitative approach. The results of the analysis were 15 captions indicating ineffectiveness that can be divided into: 6 data from foreign language influence, 2 pleonasm, 4 ambiguity, 1 logical reasoning, 1 unclear core element, 3 regional language influence, 1 word preposition wastefulness, 3 contamination, and 6 inaccurate word forms.