To provide an auxiliary cover mountable to a stroller with a hood part and having a sunshade or insect repellent function.

The auxiliary cover 10 has a hood cover part 1 and a front cover part 2. The hood cover part 1 includes an arcuate frame part 11 and a bag-like covering sheet part 12, and has mounting means 16 to the stroller 4 at both ends of the arcuate frame part. The front cover part includes a bag-like protective sheet part and a drawstring type adjusting means. The drawstring type adjusting means includes a string-like cord member, an annular opening part and a string-like cord member locking means. An extensible chord type edge part of the hood cover part is connected to the upper part of an extensible elliptic edge part of the front cover part to connect the hood cover part to the front cover part. When a stroller auxiliary implement is mounted, the hood cover part can cover a stroller hood part from the outside and project forward from the front end of the hood part, and the front cover part covers the front part of the stroller. The annular opening part is provided in a position covered with the hood cover part.