Classification accuracy can be used to evaluate a Linear Regression model. code example
Example: how to find the accuracy of linear regression model
import numpy as np
import matplotlib.pyplot as plt
import pandas as pd
dataset = pd.read_csv('Salary_Data.csv')
X = dataset.iloc[:, :-1].values
y = dataset.iloc[:, 1].values
from sklearn.cross_validation import train_test_split
X_train, X_test, y_train, y_test = train_test_split(X, y, test_size = 1/3, random_state = 42)
from sklearn.linear_model import LinearRegression
regressor = LinearRegression()
regressor.fit(X_train, y_train)
y_pred = regressor.predict(X_test)
print('Coefficients: \n', regressor.coef_)
print("Mean squared error: %.2f" % np.mean((regressor.predict(X_test) - y_test) ** 2))
print('Variance score: %.2f' % regressor.score(X_test, y_test))