In a phone message to parents, Superintendent Steven Lawrence said the student was walking on Glazier Drive in Concord when a man in a beige van approached her and repeatedly asked her to get into his vehicle.
The student declined and walked away from the van, but the man continued to offer her a ride. She repeatedly told the man "no," and went to a safe location, where she called a parent to pick her up, Lawrence said.
The parent drove the seventh-grader to school, where the she described the suspect to administrators as a bald, heavyset man in his 30s with a black goatee and mustache, possibly of Polynesian descent, Lawrence said.
Lawrence urged parents to remind their children not to speak with strangers, and to tell an adult immediately if a stranger approaches them.
Lawrence also urged students to walk in groups.
"There is safety in numbers," Lawrence said.